SEM Image Gallery

SEM micrograph of a fractured diatom frustule from diatomaceous earth. The image shows a hemispherical skeleton of a diatom, a type of algae, at 12000x magnification. The diatom frustule is composed of silica and displays a porous, honeycomb-like structure. Imaging conditions were 10.0 kV accelerating voltage using a mix of 50% BSD and 50% SED signals. Diatom’s porous structures make them useful for filtration, oil absorption, and as an abrasive material.

Sem micrograph of ash from a wood fire. The image shows the non-combustible residue left behind after a wood-fire. The image was acquired at 9500x, using 10kV and a mixture of 58% SED and 42% BSD. The composition of ash varies, but it is often rich is calcium because it is an essential component in plant cell walls. The structures shown were confirmed to be rich in calcium along with potassium using EDS.

Scanning transmission electron micrograph of mammalian kidney tissue. The image was acquired using the Phenom Pharos field emission desktop SEM equipped with a scanning transmission electron microscopy (STEM) detector at 20000x magnification. Imaging conditions were 20.0 kV accelerating voltage. The STEM mode enables visualization of ultrastructural details, facilitating the analysis of kidney morphology and aiding pathological diagnosis.

Scanning transmission electron micrograph of mammalian pancreatic tissue. The image was acquired using the Phenom Pharos field emission desktop SEM equipped with a scanning transmission electron microscopy (STEM) detector at 75000x magnification. Imaging conditions were 20.0 kV accelerating voltage. The STEM mode enables visualization of ultrastructural details, including the mitochondria seen in this image, facilitating pathological study.

SEM micrograph of a fractured grain of pollen from a white pine. The pollen was imaged using a field emission desktop SEM at 4100x magnification with a secondary electron detector at 15.0 kV accelerating voltage. The image reveals the elaborate exterior ornamentation and porous interior microstructure of the pollen grains. The pores and internal cavities provide an interconnected network that facilitates nutrient delivery during pollen tube growth - a detailed morphological view enabled by high resolution.

Plumber's tape (polytetrafluoroethylene, PTFE) at 25000x magnification. The image was acquired using a secondary electron detector at 4.0 kV accelerating voltage. The microstructure consists of elongated PTFE fibers that have been stretched and aligned lengthwise during the manufacturing process. Additionally, small aggregated particles composed of PTFE are interspersed between the fibers. This microscale resolution enables clear visualization of the PTFE structure responsible for the non-stick and chemical resistant properties of this widely used sealant tape.

Backscattered electron micrograph revealing a gypsum mineral inclusion within a pyrite matrix. The image was acquired at 3900x magnification using a backscattered electron detector at 10.0 kV accelerating voltage. Due to the atomic number dependence of backscattered electrons, the dark calcium and sulfur-containing gypsum appears darker contrasted against the brighter iron-containing pyrite. The central region of gypsum is seen encased within the surrounding pyrite. The BSD mode enables straightforward phase discrimination and petrographic analysis of an ore-forming process.

Scanning transmission electron micrograph of clay nanoparticles in dark field STEM mode. The image was obtained using the Phenom Pharos field emission desktop SEM equipped with a STEM detector at 63000x magnification and 15.0 kV accelerating voltage. The clay sample consists of plate-like crystalline nanoparticles along with thicker fractured pieces. Within the biggest piece of clay, small sub-domains within the grain are revealed by the dark field image. These may indicate voids or areas with where the crystalline lattice is oriented differently. This high resolution STEM image enables analysis of nanoclay crystal structure and particle size distribution for applications such as rheology and nanocomposite fillers.

SEM micrograph of chromosome chemically fixed during cell division. The image was acquired using a secondary electron detector at 10 kV accelerating voltage. During cell division, the DNA that makes up a chromosome becomes more tightly packed around the proteins that support the structure. This close packing transforms the chromosome into the recognizable X shapes which can be observed with both light microscopes and SEMs.

Electron micrograph of a spine from a bunny ear cactus plant (Opuntia microdasys) imaged at 1450x magnification with 10.0 kV beam voltage. Although bunny ear cacti appear fuzzy, anyone who has had the misfortune to touch them can attest to the itching and stinging the spines cause and how difficult they are to remove completely. From the image we can see that the spines have an elongated, cylindrical structure resembling a stem, with numerous sharp spikes extending outward along its length. These spikes along the spine are designed much like the barbs on a fishhook to prevent easy removal. This specialized structure is adapted to protect the cactus from animals that would try to eat it.

Scanning transmission electron micrograph of carbon nanotubes acquired in bright field mode at 150,000x magnification. Nanotube generation often uses metallic catalyst particles. Understanding the distribution of these particles after nanotube generation can be important for determining their nanotube sample’s properties, especially with regards to conductivity. Traditional SEM has a hard time determining where these particles are within a sample, but in bright field they show up clearly as dark areas within the mass of nanotubes.

Scanning electron micrograph of highly aligned carbon nanotubes acquired at 100,000x magnification using the SED. There are many different processes for the growth of carbon nanotubes, each attempting to tailor the growth to the unique application. Carbon nanotubes grown in highly aLigned "forests" show great promise for many applications as they can often support much longer carbon nanotubes. Carbon nanotubes are used in a variety of applications including filtration, optics, electronics, drug delivery, and energy storage. The rising demand for carbon nanotubes has lead to concentrated research efforts into methods for growing carbon nanotubes long, more uniformly, and quicker.

Scanning electron micrograph of prickly gold nanoparticles acquired at 50,000x magnification using the SED. This sample shows the nanostructure of "prickly gold" which is used widely for SEM alignment due to the unique structure of the gold particles. Gold has many advantageous properties including that it is highly electrically and thermally conductive, has excellent biocompatibility, and catalyzes many reactions. Gold nanoparticles are used for these properties in a wide range of applications including sensor creation, diagnostic markers, catalysis, drug delivery, and electronics.

SEM micrograph of a butterfly wing scales at 25000x magnification showing the intricate reticulated pattern. Imaged in BSD mode at 10.0 kV, the ridge network of cuticular structures forming polygonal shapes across the wing is clearly visible. At this higher resolution, the membranes spanning the ridges are also discernible as thin, porous surfaces. Small pores provide air passage for flight while maintaining the structural integrity of the wing and are also responsible for color of the scale.

Backscattered electron micrograph of pollen grains from a cactus plant (Rhipsalis pilocarpa) acquired at 5900x magnification with 10.0 kV accelerating voltage. The pollen displays a near-spherical shape with an intricate ornate surface decorated with numerous small spikes and pores. The spikes give the appearance of a prickly exterior and likely help adhere the pollen to the stigma during pollination. Detailed examination of pollen ornamentation provides information to identify the parent cactus species and understand cactus pollination biology.

Scanning electron micrograph of a semiconductor integrated circuit acquired in mixed mode using 32.6% backscattered electron signal and 67.4% secondary electron signal. The image was obtained at 490x magnification with 10.0 kV accelerating voltage. Visible are numerous solder bonding points that provide electrical connections to the tiny circuit elements within the chip via wire interconnects.

Backscattered electron mosaic micrograph of a coral skeleton (Acropora cf. cerealis). The image was acquired at 99x magnification and 10.0 kV by using multiple scans stitched together to provide an expanded field of view -- without compromising resolution -- in a feature of the Phenom Desktop SEM called Automated Image Mapping. The coral displays a characteristic growth pattern consisting of a central axial zone that contains bands with numerous small skeletal openings (corallites) where coral polyps were located.

Backscattered electron micrograph of a white coral skeleton (Porites lobata) at 400x magnification and 10.0 kV accelerating voltage. The image reveals an array of intricate spire-like skeletal structures arranged in a radial pattern surrounding a central zone. The structures likely provided protection and stability for the living coral polyps that resided within the cups at the base of each spine. Detailed examination of the coral surface architecture informs growth patterns and skeletal microstructure that impact habitat formation and reef-building processes.

Backscattered electron micrograph of melamine foam acquired at 470x magnification with a 10.0 kV accelerating voltage. The image reveals an interconnected network of melamine polymer fibers joined at varied angles, forming an open-cell foam structure. The fibers display a web-like morphology with defined intersections, giving rise to the abrasive and adsorbent properties of the foam. It's with techniques like SEM that the chemical and mechanical interactions that enable melamine foam's use as a (magic) eraser and general cleaning material are understood.

Backscattered electron micrograph of plaster imaged at 8100x magnification with a 10.0 kV accelerating voltage. The image reveals an array of needle-like crystal structures radiating outward from a central nucleation site. These lath-shaped crystals are gypsum, a hydrous calcium sulfate mineral that gives plaster its solid structure upon hydration. Detailed analysis of the plaster microstructure and crystal morphology provides insights into the curing process, material properties, and plaster strength.

Backscattered electron micrograph mosaic showing the upper surface morphology of a small starfish. The composite large area view was obtained by stitching together multiple high resolution scans at an accelerating voltage of 10.0 kV. The central disk region is visible, surrounded by individual arms radiating outward. The upper surfaces are covered by calcium carbonate ossicles and spines. Interspersed are pores of the sieve plate endoskeleton, and variable surface textures reflect differences in degrees of mineralization.

Scanning electron micrograph of a broken drill bit acquired at 1000x using the secondary electron detector. Metal has two failure modes- brittle fractures and ductile fractures. Often when a part fails abruptly, like this drill bit, it is due to a brittle fracture. Brittle fractures typically form the small round features seen this image, which can be used to study what initiated the metal fracture event.

Electron micrograph of a piece of nickel foam acquired at 3100x magnification with signal mixed from the secondary electron detector (15%) and the backscattered electron detector (85%). Typically in an image acquired by the backscatter detector darker and lighter areas indicate different chemical make-ups. The shading within the metal grains in this image show a different kind of contrast called channeling contrast. Channeling contrast is due to differing orientations in the crystal lattice of the material. The crystal lattice can differ not just grain to grain, but also within a grain. This image show many multi-zoned grains, which indicates that the metal experienced complex stresses as it solidified.

Backscattered electron micrograph of lily pollen acquired at 2300x and 10.0 kV accelerating voltage. Pollen grains act as durabe containers for plant genetic material. Many pollens have complex outer structures like the reticulated pattern of lumina and exine on these lily pollen grains. Lilies in particular show a large variation in their pollen morphology, with smaller pollen grains be favored by species adapted to more extreme environments.

Backscattered electron micrograph acquired at 3100x acquired at 10.0 kV of the inside of a shell. The shiny, iridescent interiors of shells is made up of many many layers of nacre. The nacre makes up the complex terranced structures in the image. The image shows that how irregular the thickness of the coating is on this shell. As light interacts with these layers of nacre it is diffracted and reflected causing complex interference between the light waves. The complex interactions of the light with the shell surface is what creates the beautiful shifting colors of the shell's lining.

Backscattered electron micrograph acquired with 10.0 kV accelerating voltage. This image shows a specialty sandpaper made up of resin pyramids with encased silicon carbide grains. As the sandpaper is used, more and more of the fine grit is released allowing the sandpaper to be used for a long time while delivering consistent sanding.

Secondary electron micrograph of the surface of a poinsettia leaf acquired at 5.0 kV accelerating voltage. The structures covering the surface of the leaf are epicuticular wax which functions to repel water from the leaf and minimize water loss. The morphology of these wax structures on the surface are studied to inform the design of synthetic hydrophobic coatings and as a biomarker for carbon-dating.

Stitched backscattered electron micrograph of a cucumber slice acquired using the temperature controlled stage. By freezing the sample, the complex tissue structures of the cucumber can be studied in detail without the damage drying causes to the plant cells. Automated image acquisitions are stitched together to see large scale morphologies including the structures surrounding the seeds and at the transition between the internal tissue and the skin.

Backscattered electron micrograph of calcium oxalate crystals isolated from Opuntia ficus-indica -- prickly pear -- cactus tissue. The image was acquired at 1000x magnification using an acceleration voltage of 15.0 kV. The calcium oxalate crystals exhibit well-defined shapes with jagged, spike-like edges clustered together in a spherical aggregation resembling a sea urchin. In plants, calcium oxalates function as a reserve of calcium and oxalate ions and help provide structural tissue support.

Backscattered electron micrograph of "clump and seal" slide cat litter acquired at 1000x magnification with an accelerating voltage of 10.0 kV. The clumping litter consists of granules made from sodium betonite clay coated with an adhesive polymer. The clay particles exhibit flaky platelet-like morphology characteristic of smectite clays. The polymer coating appears as an amorphous phase bridging between clay particles, enabling adhesion upon wetting. The backscattered mode provides compositional contrast between the higher average Z (brighter) clay matrix and lower Z (darker) adhesive polymer phase.

Backscattered electron micrograph of the tip of a cerium hexaboride (CeB₆) solid-state crystal used as the electron source in a Phenom Desktop scanning electron microscope (SEM). The image was acquired at a 10.0 kV acceleration voltage using the instrument's BSD. The CeB₆ crystal appears with bright contrast due to its high mean atomic number, displaying a hexagonal morphology and tapered shape optimal for drawing electrons.

Backscattered electron micrograph of a dove feather acquired at 710x magnification with an accelerating voltage of 15.0 kV. The feather barbs and barbules are clearly visible as branched structures extending outward from the central rachis. The barbules display a smooth texture while the rachis exhibits longitudinal ridges, and the backscatter imaging reveals contrast for the outer vane of the feather compared to the inner vane. The seperated barbules in the image would be realigned by the bird preening their feathers to provide lift when flying and a hydrophobic sufrace. Overall, detailed microscopic examination of feathers provides insights into the structural specializations that enable birds to fly.

Electron micrograph of graphite pencil lead acquired at 5200x magnification with an accelerating voltage of 5.3 kV. This backscattered electron micrograph shows a layered structure of a graphite-clay mixture as regions of swirling, wrinkled sheets with folded edges. Pencil leads are tyoically made from a mixture of soft clay that has a natural layered morphology and graphite. The combination allows the pigmentation and hardness of the lead to the altered by mixing the component in different ratios. The shaping process for producing the lead puts complex strains on the layers of clay, causing it to fold into the patterns shown in this image.

Secondary electron micrograph of a grass leaf acquired at an accelerating voltage of 15.0 kV. The image reveals longitudinal rows of elongated, oblong-shaped epidermal cells giving rise to the visible striping pattern. Bright contrast hairs (trichomes) are also visible protruding out sporadically from the surface of the leaf -- features that also aid in identifying the grass species.

This backscattered electron micrograph reveals a fragmented piece of Mars in stunning detail. Taken at an accelerating voltage of 15.0 kV, the surface of the 'Black Beauty' meteorite unfurls like a tapestry made from minerals. A dark, basaltic groundmass of intricately intergrown pyroxenes forms the backdrop. This matrix is punctuated by bright white lodes and veins of iron-rich oxides that meander across the surface. Between the metal threads lie specks of various sulfides that glitter like stars against a night sky. Together these materials paint a rich geological history of a diverse magmatic past on our rust-hued neighbor world.

Secondary electron micrograph of setae from a tiny red velvet mite acquired at 11500x magnification with 10 μm scale (and 10.0 kV). This little red arachnid exhibits an intricate surface morphology of intertwined, wavy folds and ridges resembling chaotic writhing structures. This complex arrangement maximizes surface area to retain moisture in the mite's arid environment. The capacity for high resolution SEM empowers research into the obscure world of tiny mites and improves understanding of microscale animal-environment interactions.

Backscattered electron micrograph of a polymer electrolyte membrane from a hydrogen fuel cell. These membranes move the hydrogen ions (protons) from anode to cathode without allowing electrons to move between the electrodes. It also separate the two chambers preventing fuel-oxidant blending during operation of the fuel cell. Improving the proton-conduction of these membranes while minimizing cost is one of the limitations in more widespread sue of fuel cells. The SEM is an excellent tool to evaluate new fabrication techniques as well as perform failure analysis on these membranes.

Electron micrograph of biodegradable beaded fibers made out of polycaprolactone (PCL) using the Fluidnatek LE-100. This image was acquired by mixing the signal of the backscatter and secondary electron detectors in a 1:1 ratio. In the past, this type of fiber morphology was thought to be a disadvantage in the electrospinning field. These days the beaded fiber structure is used for drug encapsulation, coat medical devices, increase efficiency of air filtration, among others.