Please Note: This post is a continuation of last week’s entry, “A Tale of Two Hobbies: Part 1”.
One day, Samuel Kistler, a farmer, was spreading some jelly on his toast when he wondered what was holding that gel together. It occupied a space somewhere between a solid and a liquid, and so Kistler hypothesized that by removing the liquid, he would see the solid framework that provided structure to the jelly. Kistler consulted some scientists, and both agreed that by supercritically drying the gel, they would be able to isolate the solid structure within. Some of the first tests were on egg whites and fruit jellies, and the material they discovered was aerogel. This material has amazing properties; it is a powerful insulator, and the world’s lightest manmade material. Its structure is pockmarked with holes, and looks something like this.
Diagram illustrating the principles behind aerogels’ insulative properties
Aerogels have recently been developed for numerous interesting applications. In the 1980’s, a meteor shower was going to pass close to Earth, and scientists wanted to collect samples so as to better understand our universe. Puzzled, they searched for a material that could withstand both the immense force and heat of collisions while also effectively collecting the material. They found their answer with aerogels. Because of their insulative properties and their many holes, particles could collide with the aerogel without harming it, and would remain in the aerogel for further analysis back on Earth. This was called the Stardust mission, and it is because of that innovative usage of aerogels that we collected the first ever samples from a meteor shower. Additionally, aerogels have been highly developed as insulation for houses, where they can be many times as effective as traditional insulation. There are jackets whose linings are composed of aerogels. The initial prototypes for these jackets were so effective that when they were worn climbing Mount Everest, climbers became too warm and had to unzip.
Aerogels can also be given properties traditionally associated with metals, such as shape memory. At Missouri S&T, researchers have been working to improve this technology. When these particular aerogels are deformed from their original shape, just a little bit of heat will return the material to its original position. This technology’s applications include projects as monumental as biomimetic hands, which, due to the flexibility and versatility of aerogels, could be groundbreaking.
Time lapse photo of a shape memory aerogel returning to its original position after a deformation
A biomimetic hand utilizing shape memory aerogels
This diversity in the applications of aerogels are due largely to the wide range of compostitions they can have. Aerogels range from silica, one of the first materials developed, to carbon, metal, and metal oxides. Each type of aerogel has different properties, and open the pathway for new developments.
It is amazing to think that such important developments in the field of Materials Science and Engineering could come from such simple hobbies as canning and origami, but this is the case. We never know where the next development will come from; it could feasibly be hypothesized from another hobby, perhaps even one of yours. You never know.
Thank you so much for reading, and I look forward to presenting more intersections of history, MATSE, and anthropology in the future.