Aerogel’s extraordinary properties are due in large part to its structure. Aerogel is a solid but on the nanoscale it has a mesh or sponge-like structure. The struts of this structure are nanoscale, as are the pores at around 20nm across. This makes silica aerogel incredibly light (it was once the lightest solid but has now been superseded by graphene aerogel), transparent and adsorbent.
An ice-cube sized piece of aerogel has an internal surface area roughly equal to half a football field. Aerogel is used in high end museum cases to regulate humidity. Plus it helps maintain the vacuum on the Mars Insight seismometers - it adsorbs moisture and other outgassed volatiles that come from the spacecraft itself. Proposed uses include as a physical insecticide by ‘drying out insects’ reducing the need for chemical and toxic pesticides.
Oh jeez why whould you coat your whole body in this… I have yet to hear of any decent studies on the safety/handling risks of aerogel… I’m pretty sure that the structure can fragment into small enough/nanoscale particles that can be absorbed by the body and cause harm… Not to mention respiratory issues from such small particles.
Respiratory concerns were mentioned in the video. The body can expel the molecules. They are not shaped like asbestos, fiberglass, or other items that the body cannot expel. Now, too much of anything is bad, but they didn’t mention how much it would take to coat your lungs and prevent too much oxygen absorption.
Aerogel can be made of many substances. The most common is silica but not the only kind. I’m not certain what kind was used.