PRODUCTS

JEOL USA Blog

JEOL USA blog

rss

Items of interest for the JEOL community

Carbon Nanotubes imaged by TEM (L) and SEM (R)

[photo: Carbon Nanotubes imaged by TEM (L) and SEM (R)]

Electron microscopy has revolutionized the imaging of nanostructures. With its excellent sub-Angstrom spatial resolution, electron microscopies can be used to image objects as small as atoms on a surface.1 For high-precision manufacturing of nanoscale structures, such high spatial resolution is essential for quality control and checking for the presence of any defects in the structure that may impede performance.

The reason electron microscopy has such high spatial resolution in comparison to traditional optical techniques is due to the much shorter wavelength of an electron compared to that of a photon. In optical microscopes, this limits the apparatus to a spatial resolution of several hundred nanometers. 

Two of the most popular electron microscopy methods make use of scanning electron microscopes (SEM) and transmission electron microscopes (TEM). Scanning electron microscopes and transmission electron microscopes require slightly different sample preparation and recover different imaging information but many of the basic operating principles are similar between the techniques.

Basics of Electron Microscopy

Most electron microscopes are composed of the electron source, typically a high voltage electron gun, a series of focusing optics, the sample holder, and a detector. High brightness electron guns produce the electron beam that is then focused onto the sample. The focusing optics in an electron microscope play an important role as changing these conditions affects the depth of field and illumination area of the electron beam. After interacting with the specimen, the scattered electrons are collected in various geometries to reconstruct an image.

What is the Difference Between SEM and TEM?

The positioning of the detector and the type of electrons detected is one of the key differences between scanning electron microscopes and transmission electron microscopes.2 In a transmission electron microscope, the electron beam passes straight through the sample where the change in the electron transmission is detected.

Transmission electron microscopy is ideal for thin layer samples (< 150 nm) and can be sensitive to not just the surface of the sample but the inner regions as well. It is commonly used for highly crystalline structures and nanotechnology applications but can be used for looking at tissues and bacteria as well.3

Scanning electron microscopes instead detect the backscattered and secondary electrons from the sample instead of just detecting the incident beam. When combined with raster stages to translate the sample, a scanning electron microscope can be used to reconstruct a full structural image.

Both scanning electron microscopes and transmission electron microscopes are ‘label-free’ microscopy techniques and image the sample as it is. However, for imaging with scanning electron microscopes, one of the big challenges is ensuring the sample can withstand the high vacuum conditions and is sufficiently clean to capture the incredibly detailed images the technique is capable of.

JEOL Microscopes

JEOL offer an extensive range of scanning electron microscopes and transmission electron microscopes.2 Contact JEOL today to find out what the right technique for your application is and how their instrumentation can benefit you.

References

  1. Smith, D. J. (2008). Ultimate resolution in the electron microscope? Materials Today, 11, 30–38. https://doi.org/10.1016/S1369-7021(09)70005-7
  2. JEOL (2022) Scanning Electron Microscopes, https://www.jeolusa.com/PRODUCTS/Scanning-Electron-Microscopes-SEM, accessed April 2022
  3. Arenal, F. L., A., D., & R., M. (2015). Advanced transmission electron microscopy. Springer



Comments are closed.
Benchtop SEM

Tabletop SEM Imaging Workflows from JEOL

Tabletop SEM Imaging Workflows from JEOL

Tabletop SEM Imaging Workflows from JEOL
Scanning electron microscopes (SEMs) are among the most powerful research tools as they have a much larger depth of field than optical microscopes and dramatically higher magnifications, combined with the ability to conduct chemical analyses using spectroscopic methods.
SEM imaging is such a versatile tool that critical objectives (i.e. visualising microstructures) can often be obtained via a single image. However, this is insufficient in situations where scientists are hoping to resolve a range of material properties with various implications for future technologies. Such research objectives typically demand a multidimensional approach, whereby SEM imaging is combined with a unique workflow of additional testing equipment.

Integrated Workflows via Tabletop SEM Imaging

SEM imaging has historically been limited to large laboratories with the budget and space to justify the installation of full-scale scanning electron microscopes. The genesis of compact SEM instruments designed to fit on a benchtop have altered that landscape, and the onset of new technologies has made it possible to integrate additional testing equipment into SEMs, creating self-contained nano-laboratories.
At JEOL, we offer tabletop workflow solutions that enable researchers to establish a compact and user-friendly environment for robust analyses using SEM imaging and a combination of chemical, electrical, and/or mechanical test equipment. This enables users to seamlessly prepare, test, and analyse various samples in a single unit, without ever compromising data integrity.

SEM Imaging Workflows: Components for Sample Preparation

In addition to providing seamless navigation and cross-referencing; real-time embedded chemical analysis; particle and fiber analysis; and 3D topographical analysis, our SEM imaging workflows come with auxiliary components that ensure the integrity of your results by preparing optimal samples for analysis. These include:
  • The Smart Coater is a compact and fully automated sputter coating device used to apply an extremely fine-grained carbon or metal coating over non-conductive specimens with exceptional consistency. This thin conducive film effectively eliminates charging of non-conductive samples and can enhance the emission of secondary electron emission for clearer SEM imaging.
  • The Ion Beam Cross Section Polisher (CP) is a high-speed milling device which uses an argon beam to polish pristine cross sections with wide areas of preparation. This technique eliminates the artefacts typical of mechanical milling, instead producing defect-free sample cross sections without contaminating them in any way.
These integrated solutions enable users to prepare immaculate samples prior to SEM imaging. If you would like to learn more about the additional features of our tabletop SEMs, read Compact Tabletop Imaging and Analysis Workflows – A Multidimensional Approach.

Looking for SEM Imaging Solutions?

JEOL is the industry-leading manufacturer of innovative SEM platforms, with experience stretching back to the early 1960s and the inception of the world’s first commercial SEMs. Alongside practical applications support and training, we offer comprehensive workflow solutions that empower microscopists to obtain the best images possible of their samples. This is paramount in exploring new generations of macro- and nanoscale materials, for investigating critical quality issues, and for a host of emerging applications that can only be enabled by robust multidimensional analysis. Explore our SEM imaging solutions to find out which SEM is right for your application.

Fig. 1. EDS map of LiB cathode at 1.2kV, 6nA, 10kX. The map shows the distribution of C, F, Co, and O. Taken with JEOL FESEM.

Designing Better Batteries Through Innovative Microscopy Characterization

Designing Better Batteries Through Innovative Microscopy Characterization

Lithium-ion batteries were commercially introduced in 1991, presenting new analytical challenges in the quest to improve the quality, safety, and lifespan of this fastest-growing battery chemistry. The basic structure of Lithium-ion batteries (LIB) contains as many as 10 different thin films that are synthesized to form at least that many solid−solid interfaces. These interfaces consist of thin layers of cathode material, insulating barriers, anode materials, metal current collectors, and the electrolyte. These various components are in the form of powders, sheets, and fluids and require an assessment before and after assembly and after repeated charge/discharge operations.
Fig. 1. EDS map of LiB cathode at 1.2kV, 6nA, 10kX. The map shows the distribution of C, F, Co, and O. Taken with JEOL FESEM.
“A significant thrust of the current research is focused on correlating electrochemical behavior to what is physically happening within the cell,” Dr. Ahmed Al-Obeidi (Ionic Materials, Woburn, Massachusetts) says. “In order to do that, one often needs to study the 3D microstructure of the battery components as well as the interfaces formed between those layers. Broad beam ion milling is a robust way to obtain clean cross-sections that provide microstructural information which, when combined with EDS, enables high spatial resolution with phase and chemical mapping. LIB composed of ceramics, metallic foils, and polymers presents a complex system that is difficult to get an artifact-free cross-section of using more traditional mechanical cross-sectioning techniques.” Ion milling is one of the only reliable techniques to get a clear sense of different layers as well as interfaces between layers (Fig. 2). 
Fig. 2. Backscatter image of LIB cross-section prepared with JEOL CP polisher.
Fig. 2. Backscatter image of LIB cross-section prepared with JEOL CP polisher.
Moreover, for the evaluation of lithium-ion battery materials that potentially react and degrade upon exposure to air, it is indispensable to have techniques to prevent the exposure of the specimen to the atmosphere. For that purpose, JEOL has established a designated workflow that includes a common air-isolated transfer vessel that is used to transfer a specimen that has been prepared in an inert gas environment (such as in a glove box) to the designated specimen preparation equipment (broad ion beam polishing equipment, Cryo Cross-section Polisher), and subsequently into the SEM through a specimen exchange chamber without exposing the specimen to the atmosphere, so that it can be observed using the FE-SEM (Fig. 3). In the example here, specimens of a lithium-ion battery positive electrode material containing LiCoO2 are first observed without being exposed to the atmosphere, and then the same location is observed after exposing the specimen to air. There are no deposits observed on the unexposed specimens, but when the same locations are observed after exposure to air, the deposits are observed. This demonstrates the effect of the transfer vessel for preventing specimen exposure to the air.
Fig. 3. LiCoO2 particles in the positive electrode before and after air exposure. Clearly, air exposure introduces various artifacts affiliated with specimen reactivity with atmospheric oxygen.
Fig. 3. LiCoO2 particles in the positive electrode before and after air exposure. Clearly, air exposure introduces various artifacts affiliated with specimen reactivity with atmospheric oxygen.
The combination of the air-isolated specimen preparation and transfer workflow and exceptional data fidelity make JEOL FE SEMs uniquely suited to meet the requirements of the LIB research needs. ‘We sent our samples to get imaged over several weeks, and they were unbelievable – really beautiful images – JEOL has a very skilled team and powerful imaging capability. All of the SEMs that we had access to (until now) didn’t have an inert transfer method, which is important for electrochemical or chemically active materials, and JEOL instrumentation offers are the necessary solutions’, says Dr. Ahmed Al-Obeidi. Ionic Materials are awaiting delivery this month of the IT800 FE SEM and the Cryo Cross-section Polisher.

Carrying Out Nanostructural Analysis with Focused Ion Beams

Carrying out Nanostructural Analysis with Focused Ion Beams

Carrying Out Nanostructural Analysis With Focused Ion Beams

Carrying Out Nanostructural Analysis with Focused Ion Beams
Focused ion beam technologies, considered to be an emerging field within electron microscopy, are used in a multitude of scientific disciplines for site-specific analysis, milling, micromachining, deposition, and imaging. This article will serve as an overview of focused ion beam technologies and how they are used in nanostructural analysis.

What are Focused Ion Beams?

Focused ion beam (sometimes referred to as FIB) is a method that is often used in materials science, semiconductor industry, and biological fields for the analysis, deposition, and ablation of materials. A focused ion beam setup is a scientific instrument that looks similar to a scanning electron microscope (SEM).
Whereas SEMs use a focused beam of electrons to image a given sample, FIBs use a beam of focused ions to image, mill, deposit, etc. Focused ion beams can be incorporated into a system in which both electron and ion beam columns are present, which means that the same feature can be investigated with either of the beams.
Dual-beam (SEM + FIB) platforms serve as multifunctional tools for direct lithography for nanostructural analysis. These platforms combine a high-resolution scanning electron microscope and a focused ion beam column which is also equipped with precursor-based gas injection systems, micromanipulators, and chemical analysis tools.

What is Nanostructural Analysis?

A nanostructure is a structure of a non-specific size between microscopic and molecular structures. Nanostructural detail refers to microstructure at the nanoscale, and when describing nanostructures it is important to differentiate between the number of dimensions in the volume of an object which are on the nanoscale. Nanotextured surfaces have one dimension which is on the nanoscale such as the thickness, whereas nanotubes have two dimensions that are on the nanoscale and spherical nanoparticles have three dimensions on the nanoscale.

Using Focused Ion Beams to Carry Out Nanostructural Analysis

Focused ion beam milling enables manipulation of the shape and size of nanostructures to create geometries that may be useful for thermoelectrics, optoelectronics, and quantum computing.
At JEOL, we are experts in metrology and analytical instruments. If you would like to find out more about how we can help with focused ion beam technology, contact us today for more information.

Triple-Quad Mass Spectrometer

A Quick Introduction to Triple-Quadrupole Mass Spectrometry

A Quick Introduction to Triple-Quadrupole Mass Spectrometry

Triple-Quadrupole Mass Spectrometer
Mass spectrometry (MS) is an analytical tool used in chemical analysis to identify unknown compounds, quantify known compounds, and investigate the chemical properties of target analytes. A basic mass spectrometer consists of an ion source, a mass analyzer, and a detector, and each part has a variety of different technologies that can be leveraged to tailor the analysis for very specific applications. The type of MS is typically defined by the mass analyzer, and there are a variety of mass analyzers to choose from: time-of-flight, magnetic/electric sector, linear quadrupole, quadrupole ion trap, and ion cyclotron resonance, to name a few; and each mass analyzer has a variety of sub-types to enhance or change the functionality. This blog will focus on triple-quadrupole mass spectrometry.

Quadrupole Mass Analyzers

A quadrupole consists of paired metal rods arranged symmetrically around an axis. An electric field is generated when DC electrical voltage is applied across a pair of rods, and opposing polarity DC voltage is applied to the other paired rods. By adding RF voltage to both sets of rods, oscillations can be induced in ions travelling through the instrument. By moderating the applied RF voltage (and thus the electric field), which ions make it through the system, and which are filtered out can be adjusted. Single-quad (common parlance) mass spectrometers use one quadrupole to filter ions prior to detection, which offers basic qualitative and quantitative capabilities. 

Tandem MS

Sometimes, a single-quad instrument can’t provide the information needed, and so the ions are collided with a gas to induce fragmentation, and then these fragments are measured by another mass analyzer in tandem. This is referred to as tandem MS (or MS/MS), which can provide more details about the analyte through its fragmentation pattern. The precursor ion is selected by the first mass analyzer, fragmented in the collision chamber using a gas, and then the product ions are selected in the second mass analyzer. This process is so specific, that ion concentrations can be measured with high sensitivity and specificity.

Triple-Quadrupole MS

Triple-quad mass spectrometry technology was invented by Christie G. Enke and Richard A. Yost in the late 1970’s.  For a basic triple-quad instrument, two linear quadrupole analyzers are connected by a third quadrupole, where collision gas is introduced to fragment the ions.  Ions from analytes not of interest are discarded in the first quadrupole, the second quadrupole fragments the chosen analyte and directs the fragment ions into the third quadrupole, where they are scanned in the same manner as a single-quad instrument.  This produces an MS/MS spectrum that can be used to confirm the identity of analytes.  Alternatively, the third quadrupole can be set to monitor only specific ions.  This greatly increases the sensitivity and specificity of the analyzer, which is great for quantitative analysis.

What can triple-quad mass spectrometry be used for?

Because the triple-quad mass spectrometry offers good sensitivity and selectivity, the biggest area of applications involves the analysis of trace amounts of chemicals.  Pesticides in food, nitrosamine impurities in pharmaceuticals, and dioxin analysis are all applications that demand high sensitivity and specificity.  Triple-quads can also be good research instruments, because the pattern produced by scanning the fragment ions in the third quadrupole can provide identifying information for an analyte of interest.  The same data can also be used to elucidate properties about the chemical.

Where can I get more information?

For a deeper insight into the power and precision of triple-quad mass spectrometry, refer to our JMS-TQ4000GC product page. Or contact a member of the JEOL USA team today if you have any questions.  There is also a good C&EN article that explains the history of the triple-quad.  Finally, the original paper about the invention of the triple-quad by Enke and Yost can be found here.

SEM Image of Kidney Tissue

TEM vs. SEM Imaging: What's the Difference?

TEM vs. SEM Imaging: What's the Difference?

TEM image of kidney tissue
TEM image of kidney tissue
SEM image of kidney tissue
SEM image of kidney tissue
Both TEM (transmission electron microscopy) and SEM (scanning electron microscopy) use electrons to acquire images of samples and they both use an electron source, a series of electromagnetic and electrostatic lenses which control the trajectory and shape of the electron beam and electron apertures, all housed within a chamber under a high vacuum.
Both TEM and SEM imaging technologies use focused electron beams as a source of illumination, meaning that the images produced are at a significantly better resolution than light-based microscopes. The key difference between SEM imaging and TEM is that SEM produces an image by detecting secondary or backscattered electrons, whereas TEM uses transmitted electrons to form an image. 

The Basic Principles of TEM Imaging

TEM imaging is based on a beam of electrons passing through and interacting with an ultra-thin specimen; the transmitted electrons are then recorded with a camera further down the electron column. For this reason, TEM can give vital information regarding the inner structure of samples such as crystal structure, stress state information, morphology at the atomic scale, whereas SEM imaging offers valuable insight into the sample’s 3D surface and composition.
Since the sample must be very thin to allow electron transmission, the number of materials specimens that can be viably imaged is limited adding a difficult and expensive sample preparation step to the imaging workflow.
TEM imaging can achieve excellent spatial resolutions, with resolutions of less than 50pm being reported whereas SEM imaging is limited to ~0.5 nm.

SEM Imaging Basics

SEM imaging is very popular with scientists in the materials and life science research areas as its resolution and depth of field capabilities are a significant improvement on those of traditional optical microscopy. SEM imaging uses deflector coils which alter the path of the electron beam so it scans a sample in a raster pattern. Typically, three detectors are positioned at angles in the sample chamber, these are an X-ray detector, a back-scattered electron detector, and a secondary electron detector. None of these elements are reliant on transmission, meaning sample thickness is not a significant issue.
This does cause a relative drop in resolution; however, SEM imaging offers 3D surface mapping whereas TEM imaging offers 2D internal imagery.

Choosing between TEM and SEM Imaging

The choice of whether to use TEM or SEM imaging comes down to three considerations: 1) required resolution; 2) speed and ease of analysis; 3) ability to adequately prepare the specimen. SEM imaging is often considered the quicker, more versatile, and convenient option as TEM sometimes has issues with material applicability which can only be resolved through a time-consuming thinning process. TEM, however, allows for more resolving power and the ability to visualize and analyze atomic level information.
At JEOL, we create equipment for both TEM and SEM imaging and our experts can advise you on which process will work best for your application, just contact us today for more information.

Understanding the Basics of 3D Electron Microscopy

Understanding the Basics of 3D Electron Microscopy

Understanding the Basics of 3D Electron Microscopy

Understanding the Basics of 3D Electron Microscopy
Electron microscopy is an extremely powerful analytical tool used to characterize a near limitless range of sample types, regardless of their material class. This outstanding versatility is coupled with exceptionally high spatial resolutions that far outstrip the capabilities of conventional optical microscopy. In fact, it seemed for a while as though the technological advances of electron microscopy faced ever-increasing resolution with no obvious barriers to infinitely-improving performance.
A relatively novel frontier in improving the depth of metrological data that electron microscopy can provide is three-dimensional (3D) electron microscopy.
In 3D electron microscopy, multiple sets of stereoscopic images taken from a range of viewing angles are collated and digitally constructed into a three-dimensional dataset. It is similar to computed tomography (CT) where samples are imaged as a series of two-dimensional cross-sections. Consequently, 3D electron microscopy is sometimes referred to as electron tomography.
To understand the basics of 3D electron microscopy, it is worth recapping the fundamentals of the two primary types of electron microscopes: SEM and TEM.

The Basics of SEM & TEM

Optical microscopes that use visible light to illuminate sample materials are limited to resolving features that are no closer than 200 nanometres (nm). Electron microscopes, by comparison, can readily achieve spatial resolutions approaching the sub-nanoscale – or magnifications greater than 1,000,000x.
However, optimal spatial resolution varies depending on microscope configurations. Scanning electron microscopes (SEM) are typically limited to resolutions of around 0.5 nm while the resolution of high-power transmission electron microscopes (TEM) may extend into the picometre (pm) regime.
It is worth exploring the differences between SEM and TEM in more depth at a later date, but for the purposes of understanding how 3D electron microscopy works, it is enough to know that both techniques use a focused electron beam to probe samples and obtain images based on secondary, backscattered, or transmitted electrons.
SEMs can be used to acquire high-resolution 3D surface images for specimens of any thickness, and typically offer greater flexibility and lateral range than TEMs, which are limited to extremely thin samples. However, TEMs can provide a 2D projection image of the inner structures of various sample types with significantly better resolution than SEMs.
The Principles of 3D Electron Microscopy

The Principles of 3D Electron Microscopy

Although the differences between SEMs and TEMs seem significant, the principles of 3D electron microscopy do not vary dramatically by microscope configuration. Datasets acquired from either type of microscope can be readily converted into a high-resolution 3D model using the right software. The simplest approach to 3D electron microscopy is to take a pair of stereo images of the same surface but with differing tilt angles (via physical tilt or more recently by utilizing segmented detectors). Intuitive software is used to identify homologous points between the two images, yielding highly accurate 3D coordinates that are used to create a true 3D digital representation of the sample.
The benefits of 3D electron microscopy are profound, enabling researchers to obtain extremely detailed height maps of surface topographies, or of the finest internal structures at the smallest possible range.

Plum Island sand

Why is the Sand Purple at Plum Island Beach?

Why is the Sand Purple at Plum Island Beach?

The content of youTypical New England beach sand differs in color from light and dark grey to medium tan based on its common mineralogy, but at Plum Island Beach there are swatches of purple sand that appear haphazardly as one walks along the shore. The beach spans much of the length of Plum Island, an 8-mile long barrier island that takes a beating from the Atlantic Ocean in stormy weather. Tall dunes separate the beach from thickets, marshes, and a river that comprises the Parker River Wildlife Refuge established in 1942. At any given time, visitors can see seals on the beach, raptors, now including bald eagles, waterfowl, shore and song birds. In spring the beach is closed to allow Piping Plovers to nest. And in the mid-summer bravery is required to withstand the onslaught of the fierce biting green head flies.r post goes here. Drag any of the available blocks to create a stunning post and unleash your creativity:
When three coworkers from JEOL walked Plum Island Beach early in January they were hoping to spot a Snowy Owl perched high in the dunes where they have been known to appear in recent winters. Walking along the beach they noticed numerous bands of purple in the sand and wondered what had caused them: were they man made, pollution, rotting or decaying organic material or something in the sand's composition? They appeared randomly and yet frequently at the base of the dunes above the normal high tide line. One of the walkers gathered a handful of the purple sand and put it in his pocket to bring back to ask the company's geological experts for their opinion, and to have it analyzed using one of the JEOL scanning electron microscopes (SEM) and energy dispersive X-Ray spectrometers (EDS) with a little bit of optical microscopy prior to introduction into the SEM/EDS. JEOL USA, Inc. located in Peabody, MA, supplies much of the research world with SEMs that make it possible to see things at extremely high magnifications and also analyze them for their chemical composition.
At first look under the optical microscope, the granules of sand appeared like scattered jewels of many colors; predominantly glassy pink angular grains, with smaller quantities of milky white rounded grains, clear angular grains, black grains (some magnetic and some not), and even the occasional green.
What could be the cause of the purple color? The answer was one that came as no surprise to the scientist, but was exciting for the beach walkers because they had an exact answer to a question that no doubt is one that many people have when they visit Plum Island - which was actually named for its beach plum bushes, not the plum-colored sand.
When large amounts of fine grained pink is intermixed with a smaller number of darker grains and dampened by rain or sea water the human eye will “see” the sand as a much darker pink to almost purple. The two most common pink minerals are rose quartz (while quartz is one of the two most common minerals on earth, the pink rose quartz variety is not so common ,especially in the New England geology, and is found only in a few isolated pegmatite deposits in NH & southern Maine which are where most gemstones originate) and the solid solution series of almandine and pyrope garnet which is also a very common mineral (and is quite common in the Seacoast area from the abundance of metamorphic rocks called mica schist and from contact metamorphism. This is also why many commercial sandpaper products have a pink color as the angular hard gains of almandine / pyrope garnet are the perfect abrasive. The most likely candidates for the white and clear are any of the feldspars and or quartz. The green is most likely epidote. Just based on the optical examination these are no more than educated logical guesses (but still guesses).
Vern Robertson, JEOL’s SEM Technical Sales Manager, originally examined the grains under a low power optical stereo microscope with the above conclusions. In addition to providing technical and scientific support to JEOL SEM customers for a multitude of applications, Vern holds a degree in Geology. After a cursory look optically, it was time to get down to some spectroscopic analysis to determine the actual mineral species present in the sand.
Individual grains of various colors were selected and mounted for examination with the JSM-6010LA+ InTouchScope SEM and for analysis using EDS. The SEM allows much higher magnification imaging with greater depth of field than a traditional OM and the low vacuum capability allows examination of the sample without the traditional conductive coating that needs to be applied for SEM imaging. However, it generates images in only black & white (electrons have no color!). One specialized detector in the SEM, the Backscatter Electron Detector, yields images with the gray level intensity directly proportional to the average atomic number (or density). This means that minerals containing only lighter elements like O, Si are darker in appearance to minerals that contain heavier elements like Fe or any of the metallic or rare earth elements.
Once located, each grain can be analyzed with the EDS. When an electron beam hits a sample it creates not only an image from the emitted electrons but creates X-rays, which when collected in a spectrum, indicate what elements are present and at what concentrations. This allows not only the elemental composition of the individual grains to be determined but the concentrations can be compared to known stoichiometry of the suspected mineral grains. The combination of color and magnetic properties from OM examination and the chemical makeup of the individual grains yield the answer.

The purple color (or more appropriately, pink color) comes from the abundance of almandine-pyrope garnet with a nominal solid solution composition of Fe3+2Al2Si3O12 to Mg3+2Al2Si3O12. As expected, the white grains are a mix of feldspars but mostly K-feldspar (potassium alumino-silicates) and quartz SiO2. The black nonmagnetic grains were a mix of a pyroxene called augite which showed its characteristic strong cleavage, (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6 , and a mix of ilmenite FeTiO3 and hematite Fe2O3 which are the magnetic components. The green was confirmed to be epidote Ca2(Al,Fe)3(SiO4) 3(OH). With the exception of the high concentration of garnets the rest are common minerals one would expect to find in sands.

While analyzing loose, irregular, as-received grains is not optimal for quantitative elemental analysis (high precision and accuracy quantitative analysis requires the samples be: clean, flat, polished, homogeneous at the scale being analyzed, and compared element by element to known similar matrix standards) the resulting standardless EDS analysis produced results that matched the known stoichiometry for these minerals nearly exactly.
The other item of note is that the sand is very angular and not rounded like one would expect in surf-tossed, coastal, oceanic beaches where the constant grinding of the grains by the tides would remove all sharp edges over time producing a “frosted” appearance like sea glass. Plum Island is a barrier island. This purple sand is high above the high tide high water mark and is a remnant of the initial deposition when the last glacial ice age began to recede and melt and dropped the sediments it had accumulated and pushed forward during its advance. These sediments likely come from tens to hundreds of kilometers away from their current resting place. 
The Seacoast area is full of evidence of glaciation if you know what to look for like: HUGE boulders in a seemingly odd place pushed & dropped there by the massive ice sheets, shiny, striated, polished rock faces from the immense rubbing pressures as the glaciers overtook the land, barrier islands like Plum Island and even Boars Head at Hampton Beach, NH which is a terminal moraine or the farthest point the glacier reached on its southward march before retreating and leaving a pile of debris much like the snow plows of this winter would have done.
The Scanning Electron Microscope with an Energy Dispersive X-ray spectrometer (SEM/EDS) is a powerful tool not only in academia and industry but also in answering the vexing questions of: who, what, where, when & how of items encountered in everyday life.

Some Thoughts on Why You Want to Use Low kV Imaging

Some Thoughts on Why You Want to Use Low kV Imaging

Some Thoughts on Why You Want to Use Low kV Imaging

Some Thoughts on Why You Want to Use Low kV Imaging

The benefits of low kV imaging include:

  • There is less sample damage especially on biological or polymer samples,
  • Nonconductive samples can be imaged without the need to apply a conductive metal or C coating which can totally obscure surface information,
  • Thin or nanoscale surface structures that may be invisible due to beam penetration at high kV (surface sensitivity) are now easily visualized,
  • The edge effect artifact which washes out edge, corner and surface contrast is dramatically reduced due to the small excitation volume,
  • Low kV also improves EDS and WDS spatial resolution for the same reasons as it does so for BSE imaging.

COVID-19 Virus using correlative FESEM and Fluorescence Microscopy

COVID-19 Virus Using correlative FESEM and Fluorescence Microscopy

COVID-19 Virus Using correlative FESEM and Fluorescence Microscopy

COVID-19 Virus using correlative FESEM and Fluorescence Microscopy
Professor Simon Watkins' lab at University of Pittsburgh, in collaboration with JEOL USA, has been developing novel ways to analyze biological structures in 3D, utilizing correlative FESEM and fluorescence microscopy. The paper “Correlative Fluorescence and Electron Microscopy in 3D – Scanning Electron Microscope Perspective” (Current Protocols in Cytrometry) describes how the ability to correlate fluorescence microscopy and electron microscopy data obtained on biological specimens bridges the resolution gap between the data obtained by these different imaging techniques. From the abstract: “In the past such correlations were limited to either EM navigation in two dimensions to the locations previously highlighted by fluorescence markers, or subsequent high-resolution acquisition of tomographic information using a TEM. We present a novel approach whereby a sample previously investigated by FM is embedded and subjected to sequential mechanical polishing and backscatter imaging by scanning electron microscope. The resulting three-dimensional EM tomogram of the sample can be directly correlated to the FM data.”
Early in the COVID-19 outbreak in 2020, Jonathan Franks, Lab Manager in the Watkin’s lab, applied this methodology to achieve a stunning image elucidating the interaction of COVID-19 particles with cells. We look forward to more published results on this study using correlative EM/FM.
Meanwhile they continue to use the method and, Franks says, “This technique of using the Backscatter Electron Detector to take TEM-like images has a wide range of uses.  We have continued to develop this CLEM technique to help collaborators look at a variety of tissues like neurons in a mouse brain as an example.  We also see the potential for this technique to be able to look at a much larger area of tissue than traditional TEM.  With TEM we are limited to ~1mm x 1mm x 70nm section.  The SEM equipped with the BED, we can scan up to ~1cm squared piece of tissue and can stitch together a montage of multiple images at EM resolution.”
Sample: Plaque Assays using vero-E3 cells.  Cells are on either side of the image and in the center is space between the cells where the virus is being released.
Credit: Jonathan Franks, with additional credit to William Klimstra and Alan Watson for providing the samples, Donna Stolz and Mara Sullivan for doing the sample processing.

Paper Mask 1kV 350
JEM-1400

Delta College Adapts To New Routine With Online Microscopy Training And New Technology

Delta College Adapts to New Routine with Online Microscopy Training and New Technology

In March 2020 we found ourselves in the midst of a global pandemic, and our schedules and lifestyles suddenly changed. For college students who were halfway through a semester, the pandemic put a stop to classes and campus life, and they had to pack up and go home. It also meant that their instructors were left with unfinished plans and had to quickly adapt to new ways of teaching online.
Students studying for a certificate in electron microscopy at Delta College in San Joaquin, California had just moved on from theory and were getting hands on experience on an electron microscope when the school’s doors had to close. Thanks to a solid foundation in the science, instructors could continue teaching though they had to modify their techniques and didn’t have the same access to the SEMs and TEMs in the lab.
“We’re dry labbing everything,” says Frank Villalovoz who is continually finding new ways to explain concepts such as EDS and keep students engaged without the feedback of the process on the SEM. Using his teaching skills, he calls on them by name to respond to questions in their online meetings held at the same time as their class would have been. Meanwhile lab manager Cathy Davis is keeping things running and videotaping work done on the resident TEM for beginners, a 100CX, so the students will be able to see but not touch. Students who are scheduled to be back in the fall will be able to put these concepts to work themselves.
Delta College was in full swing last fall and celebrating its 50th anniversary when Frank presented a paper co-authored with Cathy at M&M 2019 on the school’s renowned work in teaching new microscopists. It was a part of the Technicians Forum Round Table entitled "Fifty Years of Light and Electron Microscopy".
Meanwhile no one except Cathy has had a chance to try out the shiny new TEM just waiting in the lab. She had just signed off on the installation of a new JEM-1400 Flash TEM when everything came to a halt. In order to learn how to use the new TEM herself, she was able to connect with JEOL’s TEM applications scientist Kevin McIlwrath who resides nearby. Kevin is also helping the instructors with lectures on advanced EDX, comparison of 120kV TEMs to higher voltage (200-300kV) TEM/STEMs, and imaging and analytical tomography. Of course, social distancing prevails!
Like any proud new owner, Cathy is anxious to get the new 1400, a 120kV TEM that is probably the most popular in its class for use in schools, hospitals, research labs, and materials, to work. She had a special plastic cover made for the JEM-1400 table, and it sits pristinely in the lab, yet idle, waiting for a new semester to begin whenever life returns to a new version of normal and schedules can resume.

Rhinoceros
Thomas G. Huber: November 18, 1936 - December 2, 2019

Thomas G. Huber: November 18, 1936 - December 2, 2019

Thomas G. Huber: November 18, 1936 - December 2, 2019

JEOL USA is saddened by the passing of its former President, Thomas G. Huber on December 2, 2019. Those who knew him often recall his larger-than-life personality, positive influence on employees and company culture, and his deep connection to the scientific community. Tom was the driving force behind the formation of the USA subsidiary of JEOL, Ltd. in 1966 and after 37 years of leadership retired as Vice Chairman Emeritus in 2003.
Photo taken at a dinner held during the 1966 International Conference on Electron Microscopy (ICEM) in Kyoto. Tom Huber (second from the right, bottom row) and Kenji Kazato. JEOL Ltd. founder and President at that time (second from the left, back row). Tom was the National Sales Manager at the time.
Photo taken at a dinner held during the 1966 International Conference on Electron Microscopy (ICEM) in Kyoto. Tom Huber (second from the right, bottom row) and Kenji Kazato. JEOL Ltd. founder and President at that time (second from the left, back row). Tom was the National Sales Manager at the time.
Tom was instrumental in strengthening an applications and service support network as well as building a field sales staff. He founded an application training group, “The JEOL Institute,” hiring skilled applications staff in both TEM and SEM to train customers not only on what buttons to push or knobs to twist but to teach the fundamental science behind the techniques used in electron microscopy. Tom was at the helm of JEOL USA during many advances in microscopy, microanalysis, NMR, mass spectrometry, and E-beam lithography. His input to our parent company on both the technical and business aspects shaped the future of JEOL products by helping our designers and researchers understand the technology requirements of the scientific and high-tech industrial community in the Americas.
Tom was a strong proponent of and very active in both local and national societies and understood their value to both the scientific community and to manufacturers of scientific instruments. Tom always offered JEOL’s financial support and was the first President of the Microanalysis Society to come from a manufacturer. For his contributions to MAS Tom was named as part of the inaugural class of MAS Fellows in 2019. Tom’s contribution and impact on JEOL and the electron microscopy community cannot be overstated.
Tom is survived by his wife Ann, his son Todd, his daughter-in-law Meg, and grandchildren Kathleen and Thomas. Visiting hours are Friday, December 20th from 4:00 p.m. to 7:00 p.m. at the Eustis & Cornell Funeral Home i n Marblehead.

Krish Krishnamurthy

CRAFT For NMR: Challenging Conventions To Achieve Faster, More Accurate Analysis

CRAFT for NMR: challenging conventions to achieve faster, more accurate analysis

Above: Krish Krishnamurthy pictured, most likely discussing his favorite topic.
NMR data contains a trove of useful information for answering a wide variety of chemical and biological problems. However, with this broad utility comes complexity. Converting an NMR spectrum into useable information is a challenge because the workflow for NMR data analysis is primarily based on manual processing and interpretation of each individual spectrum. This can be a labour-intensive process which quickly becomes unfeasible as the number of samples to analyse increases, and if the data are to be compared across samples, then the information must be distilled into tabular or numerical format to facilitate such comparisons. These needs for throughput, efficiency, and data simplification led to research in automated computational methods for NMR analysis. However, automated attempts at extracting information from Fourier transformed NMR spectra, such as chemical shifts of peaks, integrals, peak heights, etc., quickly ran into difficulties. Some of the major issues arose from artifacts introduced during the Fourier transform, including baseline issues and phase distortions. These anomalies, which the fuzzy logic of the human mind can more readily filter out and compensate for, can cause automated NMR interpretation algorithms to produce unreliable and extraneous results. Clearly, a new approach is needed.
Back in the early 2000s, Krish Krishnamurthy was leading the NMR Group at Eli Lilly and grappling with this very problem. He was frustrated by how long it was taking to analyze NMR experiments and obtaining good quality interpretation required the limited resources of the senior NMR experts. Krish and his team came up with the idea to employ the Bayesian approach (developed by Larry Bretthorst at Washington University), which meant not looking at the spectrum at all, but taking the free-induction decay (FID), time-domain data and analysing what comes out of it in a completely objective way. And that was the beginning of CRAFT (Complete Reduction to Amplitude Frequency Table).
CRAFT uses a Bayesian statistical approach to convert NMR time-domain data directly to the tabular domain. This bypasses the artifacts created by the Fourier transform when producing the spectrum and makes the automated extraction of these chemical shift and intensity data tables more reliable. With CRAFT, the spectrum (or frequency-domain data) is simply a human visualization tool for the data tables. This is in contrast to ‘conventional processes’ where the tabular domain is created from the manual interpretation of the spectrum by the spectroscopist. We have been collaborating with Krish to bring this new and revolutionary approach to our NMR customers. We recently sat down with him to discuss its evolution and potential.
We asked Krish what is special about CRAFT:
In the conventional way of doing analysis, the source of the information is the spectrum, which is the frequency domain data. Frequency domain data is two dimensional from an information point of view. Taking it into the tabular domain makes it amenable to automated and objective processing, as we are now dealing with numbers rather than a picture. The frequency domain spectrum is a picture, no more and no less, and that is the fundamental difference between analysis by CRAFT and analysis by conventional methods. In other words, A spectrum isn't a source of the information, rather a representation of the information.
CRAFT is redefining how NMR data is looked at by spectroscopists. It has redefined some of the fundamental practices in NMR because they were all based on frequency domain. A classic example of how CRAFT is benefitting users in unexpected ways is in the field of antibodies. Analysts tend to do a CPMG type of experiment to suppress the broad background signals. This background anomaly in frequency domain comes because you’re doing a Fourier Transform. When you think about it, it doesn’t make sense to add complexity to your experiment in order to fix a problem you have created by the way you choose to do your data processing. Just change your data processing method to not introduce this artifact. Similarly, when it comes to phase correction, this is done to make the frequency domain, the picture, look better. But if the picture is not the source of the information, then you don’t need to do phase correction, because there is no error and nothing to correct. With CRAFT, we are showing that you no longer need to do these adjustments anymore.
Talking about the challenges in promoting CRAFT to NMR users, Krish commented:
We are fighting the conventional wisdom of the user. The conventional wisdom for the last 50 years has been that the spectrum is the source of information, but really it is not. We are not taking away all the knowledge we have gained in the last 50-60 years of NMR evolution, we're asking people to look at it in different way using the same knowledge. We are slowly getting that message through to the market, but it will take time for CRAFT to become the accepted norm. However, we are confident that one day, it will be.
We asked Krish what he thought held the most potential for CRAFT in the future:
There are two main areas of significant potential for CRAFT, the first one is working on in-vivo imaging spectroscopy. There is significant potential to make decisions much more objectively because the materials are biologically divergent. There is an underlying increase in uncertainty and error by definition of these projects. By introducing an analytical technique that is less subjective, that increases their value.
The second area is pattern recognition. One of the things that we are guilty of in NMR is using the zoom tool to expand the region and look inside the spectrum, and we need to get out of doing this. When you think about it, structure elucidation of organic molecules is a simpler problem than many. We are working with a handful of elements, primarily C, H, N, O and maybe a couple of others. There are well-defined and simple rules about how these can be connected. NMR gives us clues to narrow the structure possibilities further, via fairly predictable and well-documented ways. When you compare that with the many complex things the world is attempting to create algorithms for, such as facial recognition, weather forecasting, self-driving cars, etc., there must be ways NMR can leverage these pattern recognition algorithms. But first we must get the data into computer-readable formats, reliably, reproducibly, and without artifacts.
Talking about the collaboration with JEOL, Krish commented:
The tool was originally built based upon what one person thought the user would do, through the collaboration with JEOL, they brought in many real-life applications, which helped us to adapt and evolve the approach to extend its usefulness. The collaboration asked quite a few practical questions about the way the tool was built and designed. This challenged us to look at how and why we were doing things in certain ways. It was really very valuable. CRAFT is an evolving technology, we are taking a staggered approach, and continuing to develop it thanks to dynamic feedback from NMR specialists such as JEOL and its customers.
JEOL offers CRAFT for Delta V1.0 with Delta V5.3.0 software. Integration of CRAFT allows the JEOL NMR user to automatically and efficiently extract the best amplitudes and frequencies from NMR data.
On the NMR Support web site, the following resources are available for registered users of Delta and how to use CRAFT with the Delta NMR software:

Naomi Miller holds sample of regolith and presented the findings of the CCMS-MIT research group at M&M 2019. Also in photo are her 8th grade teacher, Doug Shattuck (left) and JEOL collaborator Vern Robertson (right).

Middle School Students Evaluate How to Build Structures from Martian Soil

Middle School Students Evaluate How To Build Structures From Martian Soil

Above: Naomi Miller holds sample of regolith and presented the findings of the CCMS-MIT research group at M&M 2019. Also in photo are her 8th grade teacher, Doug Shattuck (left) and JEOL collaborator Vern Robertson (right).
Just think about the logistics of building on Mars. What’s the best way to get all the materials there? Wouldn’t it be easier to use the natural resources of the planet? But what resources and how would they be used to 3D print human dwellings – while actually on Mars?
That’s the problem that 8th (now 9th) grade students at Concord-Carlisle Middle School, in collaboration with Massachusetts Institute of Technology and JEOL USA, set out to solve when they responded to a NASA challenge for the development of innovative technologies to support human colonization of Mars by 2050.Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor. Duis mollis, est non commodo luctus.
Much of the Martian surface is covered with eroded basaltic material. NASA has identified similar materials on earth, and provided Mojave Martian Simulant for the research team to use. First, the students analyzed the simulant using EDS and SEM to determine the composition of the material.  Their work determined that a suitable binding material mixed with the fine-grained simulated Martian soil could be formed into structural material. The also looked at the ability of the material to withstand compression and impact forces.
Naomi Miller examines the SEM used in the CCMS-MIT research with JEOL USA scientist and product manager Vernon Robertson
Since October 2018, under the guidance of their teacher Doug Shattuck (CCMS) and Research Scientist Dr. Kunal Kupwade-Patil (MIT), the students have been investigating methods of making concrete using a Martian soil simulant. Shattuck’s class completed a six-week research program at MIT’s Laboratory for Atomistic and Molecular Mechanics, part of the Dept of Civil and Environmental Engineering headed by Prof. Markus Buehler. Additionally, Brad Johnson and his staff at the Department of Energy’s Pacific Northwest National Laboratory (PNNL) assisted with vitrifying the samples of the completed mortar that students produced from simulant and a binder.

SEM image showing diatoms in the simulant. Opinion: These may have been added to alter the SiO 2 concentration which did not match the chemistry reported in the true Martian regolith. However, it is unlikely that there will be any of these (chemically and morphologically) in the real Martian dust.

BSE Image of ultrafine sifted simulant of Martian regolith.
Suitability of Martian Regolith Material for Future Dwellings was the title of their poster presented at M&M 2019 by Naomi Miller, a CMS student and member of the rising 9th grade student research team who traveled to Portland, Oregon for the conference. The team’s work was simultaneously published in the August issue of Microscopy & Microanalysis.

Guest Blog: Seeing Is Believing – How Benchtop SEMs Are Changing the Imaging Landscape
The Nano Nemo on the Water - Armin VahidMohammadi

Science And Art Combine For Winning SEM Images

Science and Art Combine for Winning SEM Images

Title: Nano Nemo on the Water
Subject: Nano-sized layers of Ti2C particles representing the imaginary Nemo character in Pixar's "Finding Nemo" animation. Ti2C synthesized by selective etching and is a promising electrode material for energy storage devices
Credit: Armin VahidMohammadi, Auburn University
Method/Instrument: JEOL JSM-7000F.
Armin VahidMohammadi
The first thing one notices about the images that Armin Vahid Mohammadi has created is that they are visually striking. Details and shapes emerge from the background, bearing a strong resemblance to animation characters, as in two images that were awarded top prizes in 2016 and 2017.
Combining art and science is a passion for Armin, who is doing his PhD studies in Materials Engineering at Auburn University in Alabama.

First the science.

“I do research on developing new materials based on a family of 2D materials called MXenes for batteries and other energy storage devices such as supercapacitors. We have recently shown the promising application of MXenes as cathode materials for next-generation aluminum batteries in a paper published in ACS Nano. Hopefully, by using other metals such as aluminum in the future we can find safer and cheaper alternatives for the current Lithium-ion batteries,” he says.

Then the art.

“Generally, I am interested in computer graphics and since my early years in middle school I became a professional user of many different graphics programs. For these types of artworks that I do, the interest basically comes from different objects and particles in the SEM images that resemble real-life characters. Coloring these types of micro/nano-scale images gives life to them and makes them more understandable for general audiences.”
Armin first encountered the SEM as an undergraduate, then became more familiar with its use as a graduate student studying morphology of nanoparticles. He now uses the JEOL JSM-7000F SEM regularly at Auburn.
Building on his research he hopes to develop a real product that is beneficial to human life. “I believe as an engineer and a scientist, by only pushing forward to understand more without finding practical applications which can result in an improvement in people’s lives, we will not be successful. The best would be a direct transfer of science to engineering products and vice versa, which is always hard to achieve. This is the main goal for me, to apply my knowledge toward creating a real product that is much better and more efficient than other similar products, like a better battery.”

Marine Science research yields winning SEM image

Marine Science Research Yields Winning SEM Image

Marine Science research yields winning SEM image

While researching bryozoans, marine organisms, from the unprecedented transoceanic biological rafting event caused by the 2011 Japanese tsunami, Megan McCuller found the opportunity to use an SEM at a nearby college in Maine. She produced this image of a suctorian, an aquatic organism she was simply interested in seeing up close and then decided to try colorizing for the JEOL Image Contest. She also took more than 30 images for her research, some of which will be published in January.
She explains, “My work on Japanese tsunami marine debris (JTMD) was through Williams College and the Williams College - Mystic Seaport Maritime Studies Program with Dr. James T. Carlton, who is the former director of the maritime studies program and PI of the JTMD project. I did general analysis of JTMD samples, picking and sorting organisms, but am also the bryozoan taxonomist.”
McCuller is currently an adjunct in the Biology department at Southern Maine Community College (SMCC), teaching classes for the Marine Science program (Invertebrate Zoology, Ecology, Marine Biology). “Coincidentally, I mentioned to a colleague, Brian Tarbox, at SMCC that I might run into issues with my manuscript on JTMD bryozoans by not having any SEM photos (it's now the staple of accurate identification of bryozoans) and he told me we have a grant agreement with Bates College and put me in contact with Greg Anderson who runs the SEM lab at Bates. Since being introduced to Greg, I spent a good number of hours taking hundreds of SEM photos of my bryozoan specimens and have brought my SMCC students to Bates to get experience using SEM.
suctorian
“The suctorian picture was one of my ‘fun’ photos that doesn't really have a purpose other than my interest to see what a suctorian looks like up close.” The image went on to become the winner for JEOL’s December 2017 Image Contest. She also shared a compound scope image to compare.
Megan McCuller
Megan is currently applying for PhD programs, but is already a co-author on a paper published in October. “My manuscript on JTMD bryozoans is supposed to be published in January in a special JTMD edition of the journal Aquatic Invasions, which is open access.”

Image Contest Spotlight: Cian McKeown, University of Limerick

Image Contest Spotlight: Cian McKeown, University of Limerick

Image Contest Spotlight: Cian McKeown, University of Limerick

Cian has submitted 3 images that are all relevant to platinum nanostructures. We thought that the patterns that they form were interesting, so we asked the PhD candidate about his work with platinum.
"I grow platinum nanostructures using a technique called electroless deposition. This is where no external power supply is used to grow the metal, rather metal ions are chemically reduced from a liquid deposition bath. When the growth is well controlled, we produce thin, uniform films of platinum but by changing the deposition rate we can make these beautiful nanostructures.
Take a Bow!: Platinum nanocrystals grown vertically during electroless deposition. The growth pattern is due to rapid nucleation.
Take a Bow!: Platinum nanocrystals grown vertically during electroless deposition. The growth pattern is due to rapid nucleation.
So, the ‘Christmas tree’ style pattern in one of the images is caused by a very fast deposition rate where certain crystallographic planes grow more favorably. The image of the three large Pt particles standing on top of one another is a result of the autocatalytic process we use. Once some Pt is deposited onto a metal substrate, more deposition happens on top of it. This process can keep going on and on indefinitely, growing larger particles and thicker films.
Platinum Mantis: A thin film of platinum responding to applied stress in a strange way
Platinum Mantis: A thin film of platinum responding to applied stress in a strange way
And the ‘Praying Mantis’ style formation resulted from fracturing a thin platinum film. The films can generate a good deal of stress as they grow, and this image seems to show the film folding in on itself when I cut my sample in half.
All of these processes can increase the surface area of the platinum structures, which is beneficial to my work in the field of electrocatalysis."
Thank you, Cian for sharing your work with us!
All images were obtained using a JCM-5700 CarryScope.

Spider web prep

Imaging a Spider Web with the SEM

Imaging a Spider Web with the SEM

The challenge was to image the spider’s web without causing any induced stress or deformation of the structure as collected. The web was collected between two glass plates to protect the structure. The top glass plate was removed, and the sample was transferred to an SEM holder that was configured as in the Photos.
Top reference holder with cap removed.
Top reference holder with cap removed.
Top reference holder with carbon tape on the cap and with cap reinserted.
Top reference holder with carbon tape on the cap and with cap reinserted.
Top reference holder with tape pressed onto the web.
Top reference holder with tape pressed onto the web.
For illustration purposes a piece of window screen was used to demonstrate this technique, as spider silk would be too small to show up in the macro photos. A strip of conductive C tape was applied to completely surround the removable cap of a holder designed to hold polished metallographic mounts. This was then pressed onto the web and lifted off. This allowed the intact web inside the tape to be ripped away from the rest of the web outside of the tape without any stress or strain. The cap was then placed onto the specimen holder for insertion into the SEM. This type of mounting allows the microscopist to have nothing in the background of the image.
Top reference holder with tape pressed onto the web.
Top reference holder with tape pressed onto the web.
Top reference holder with tape lifted from the web.
Top reference holder with tape lifted from the web.
Vivamus sagittis lacus vel augue laoreet rutrum faucibus dolor auctor. Duis mollis, est non commodo luctus.
Top reference holder with web firmly attached showing the remaining web left behind.
In addition to preserving the structure the goal was to create a publishable image. This is often as much art as it is science. One of the main components of such an image is a very clean, featureless, completely black background. The second attribute of a high-quality image is to have as little artifact in the image as possible. Two of the most common artifacts in SEM images, especially on organic or other low atomic number materials are edge effect and charging. Edge effect is a washing out of edges, corners or small surface structures due to electron emission from a large volume of excitation between the electron beam and the sample that greatly reduces true surface morphology. This is easily overcome by lowering the accelerating voltage. With older SEMs, this meant loss of resolution, but with today’s FEG SEMs there is effectively no loss in resolution when operating at low kV.
The other artifact is charging which is a buildup of primary beam electrons on the surface of a nonconductive sample. In the past a conductive coating (either evaporated carbon or sputtered metal, typically Au, Pd, or Pt) had to be applied to make the sample conductive. Today’s FEG SEMs, with ultra-high resolution, are capable of imaging the grain structure of any metal film which has a subtle surface morphology that is not really present in the real sample. A charging sample prohibits low energy electrons, which carry surface morphology information, from escaping from the surface. This too can be eliminated at low accelerating voltages without the need to apply a coating thereby simplifying and speeding up the analysis process. The resulting images were used for the presentation at M&M 2016 and one was chosen as the cover photo for the journal BioNanoScience Vol.6, No.2, June 2016.

Spider Silk 10,000X

Students Investigate Mechanical Properties of Spider Web

Students Investigate Mechanical Properties of Spider Web

It isn't often that 8th graders inspire scientists with their class project. When a group of scientists at the Massachusetts Institute of Technology found that a spider's web from the basement had an unusual pattern, they invited a small team of middle school students to investigate its mechanical properties. Their work caught the attention of the MIT researchers and also landed a talk at M&M 2016.
With the poster at M&M 2016: 8th grader Nicholas Moy, teacher Douglas Shattuck, and Vern Robertson of JEOL.
With the poster at M&M 2016: 8th grader Nicholas Moy, teacher Douglas Shattuck, and Vern Robertson of JEOL.
Doug Shattuck, an 8th grade Concord Middle School teacher, has successfully dovetailed his classroom projects with his summer work at MIT in the Civil and Environmental Engineering department (headed by Prof. Markus Buehler, Ph.D.) where the focus is development of novel composite materials. He has also had a long-time affiliation with JEOL USA, specifically Vern Robertson, who has on occasion imaged samples of balsa wood and 3D printed models of synthetic materials for the Laboratory for Atomistic and Molecular Mechanics using a SEM at JEOL's Peabody, Mass. headquarters. During a previous school year, when balsa wood properties were being investigated in the Lab, Shattuck had his students design balsa wood bridges capable of bearing a hundred times their own weight. This was in conjunction with the atomistic modeling of how the wood fails at the atomic bonding level.
More recently, the lab had done 3D printing of spider webs to study mechanical strength and reported their findings in 2015 publications. After observing the weaving process and reviewing the micrographs, Dr. Zhao Qin, a Research Scientist, found that the structural features of the sheet web produced by an Araneidae spider were too difficult to be duplicated with synthetic materials in the similar manner as spiders. The web construction proved even more interesting because of the unusual complexities that the SEM images revealed are connected to how the spider constructs the web, a tedious work performed in an elegant way.
SEM images show the unique pattern in the junctions between the rays of this particular spider's web and the chords that helically wrap each ray.
SEM images show the unique pattern in the junctions between the rays of this particular spider's web and the chords that helically wrap each ray.
The researchers were surprised to see an "odd crossover that hadn't been seen before" - a unique pattern in the junctions between the rays of this particular spider's web and the chords that helically wrap each ray. With the goal of determining if the helically wrapped chords (shown in frames 2,3, and 4) provided any mechanical advantage when it comes to managing normal tensile forces acting on the web, the students utilized the SEM images and evaluated ways of reconstructing an analog of the web design using sewing thread and trying different designs for a 3D printed loom with which to make them. The results of their findings were originally slated for a poster at M&M as part of the Microscopy Outreach program which promotes microscopy in education as an important learning tool for inspiring future STEM professionals. When it was learned that the research had shown some unusual properties of the spider web, the poster was elevated to a platform talk.
Concord Middle School students formed a good relationship with MIT researchers during their work. Standing in the middle are MIT Prof. Markus Buehler, Ph.D., and Concord Middle School 8th grade teacher Douglas Shattuck.
Concord Middle School students formed a good relationship with MIT researchers during their work. Standing in the middle are MIT Prof. Markus Buehler, Ph.D., and Concord Middle School 8th grade teacher Douglas Shattuck.
The talk was given by 8th grader Nicholas Moy, whose parents were pleased to be able to make the trip to Columbus, Ohio for the opportunity. Shattuck accompanied him and was able to see not only how well his students were able to thoroughly investigate the challenge they were given, but also experience the other side of being a scientist, writing and presenting a paper.
This research per se helps to reveal the secret of web architecture by providing the relation between the complex web structure and its advanced mechanical function. It will also shed light on the design of strong and light synthetic composite materials with their reinforced fibers arranged in the similar way as the spider web. Shattuck's students receive a certificate for their work, and have had the unique experience of being part of a real-world science lab and following real procedures to solve scientific problems. It's an experience that surely will give them a leg up in the future should they decide to pursue science in their careers.
Complex Web Construction: A Possible Clue to Mechanical Properties

    JEOL USA, Inc.
    11 Dearborn Road
    Peabody, MA 01960
    © Copyright 2022 by JEOL USA, Inc.