In pictures: details revealed with advanced SEM

The fascinatingly diverse detail of a rat’s bronchial epithelial surface. Long, hair-like structures, known as ciliated cells, are important for the bronchi’s self-clearing mechanisms. Large, round extrusions, known as goblet cells, secrete mucous to catch dust, allergens and pathogens. Smaller rounded extrusions are brush cells — chemosensors that detect irritants. This type of imaging has been used to study the effects of malaria and smoking on the lungs.

This image shows 50 µm of solar panel surface and highlights the pyramidal structures that help trap light and reduce reflection. Photovoltaic researchers are seeking ways to optimize the texture of these surfaces, since the shape, size and uniformity of the pyramids affect optical reflectance and energy capture.

A 2 mm bee head. Honey bees have been the subject of intense research, as their numbers are declining due to the spread of varroa mites (Varroa destructor and V. jacobsoni). The mite attaches to hive larvae or the body of a bee and weakens the larvae or bee by sucking out fat bodies. Symptoms include low body weight and deformed wings, both of which have been studied using SEM imaging.

This is what 20 µm of foundation from the make-up industry looks like. A typical product like this contains 15 to 50 ingredients. The most common minerals used as a base for foundation are mica, bismuth oxychloride, titanium dioxide and zinc oxide. The spheres here are probably silica, which acts as an anticaking agent, bulking agent, opacifying agent and suspending agent. Silica also typically absorbs sweat and oil, reduces light reflection and improves spreadability.

An abalone shell made up of 0.5 µm thick tiles of calcium carbonate, or chalk, cemented together by a protein coating. The whole structure is 3,000 times more resistant to fracturing than a crystal of calcium carbonate alone. This property comes from the positive charge of the protein coating that binds to the negative charge of the hexagonal calcium carbonate tiles. This binding is weak enough that the layers can slide slightly apart to absorb the energy of a blow. Material scientists interested in biomimicry are seeking to replicate this structure to create tougher materials.

A hydrogen-absorbing alloy magnified 30,000 times. Hydrogen-storage alloys are metallic materials that can reversibly absorb and release hydrogen from the gas phase or electrochemically. These alloys are already being used in electrodes, particularly in electric vehicles, to improve performance and to avoid using common alternative materials that contain toxic lead or cadmium, as these can leach into landfill.

An image of a 300 µm region of a Peyer’s patch, a small mass of lymphatic tissue. These patches are found mostly throughout the ileum region of the small intestine, and are important to the function of the immune system. They also play a role in determining which substances must be dealt with as foreign to the gut, although this process is still little understood.

An image of a 100 µm region of a mould, featuring a sporangium, its main reproductive organ. Once released, if the small, round spores in the image land in an optimum position, they will grow root structures known as hyphae and generate more mould. This mould grew on bread.

A mast cell imaged at a magnification of 15,000. These cells are a type of white blood cell found in connective tissue. The small spherical shapes in this image contain chemical mediators, including histamine and heparin. These play a key role in immune system reactions. When a mast cell is activated during an allergic reaction or in response to injury or inflammation, these mediators are released into tissues.

An image of 100 µm-sized region of a water-absorbing polymer. These polymers are useful in cleaning and hygiene products. SEM images can be used to measure what happens to these molecules at different saturation points.