AEROGELS are some of the lightest materials in the world, and they make excellent insulation for homes, or heat shielding for spacecraft. But they are extremely difficult to make. Now, researchers have developed a new method that mimics how baby dragonflies ready their jelly-like wings for flight.
When an entomologist called in at , UK, to use her electron microscope, she thought they would just be looking at dragonfly wings to identify their species. But when she had a peek, she was taken aback. The wings were full of tiny pores, just like the aerogels her team studies.
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When dragonflies shed their larval skin, it reveals soft wings. The insects then produce sodium bicarbonate in their hindgut and rectum. When they excrete it, this chemical reacts with the water in their wings to create carbon dioxide, creating pores and drying them out.
To mimic this process, 艩iller鈥檚 team started with a jelly-like cube, a matrix of silica molecules full of water pockets. Then they added sodium bicarbonate, which interacts with the water and another chemical solvent to create carbon dioxide. That gas props up the pores so they don鈥檛 collapse (Advanced Materials, ). The material is then rinsed and left to dry for a day.
It costs about $4 to produce a kilogram of aerogel this way, which 艩iller says is cheaper than other methods.
This article appeared in print under the headline 鈥淒ragonfly wings inspire light-as-air materials鈥�