Virtually indestructible, yet it breathes like Egyptian cotton

“Your boy’s suit I designed to withstand enormous friction without heating up or wearing out, a useful feature. Your daughter’s suit was tricky, but I finally created a sturdy material that can disappear completely as she does. Your suit can stretch as far as you can without injuring yourself, and still retain its shape. Virtually indestructible, yet it breathes like Egyptian cotton” (Edna Mode)

Have you ever wondered what supehero suits are made of? Unstable molecules and whatnot are very 80s and kevlar is too Die Hard. Nowadays, it’s better to use carbon nanotubes, at least according to Batwoman … But can we really make a super strong light thin superhero  suit using this stuff?

Nanotubes (or buckytubes) are part of the fullerene family (molecules composed entirely of carbon) and similar in structure to graphite. Specifically, nanotubes have a cylindrical nanostructure with an enormous length-to-diameter ratio. They are basically a long, hollow structure with one-atom-thick walls, that can be stacked in the case of multiwalled nanotubes (MWCNT). Their specific properties depend on the angle the walls are rolled at (chiral) and their radius.

What makes nanotubes so interesting, though? Basically, they are the strongest and stiffest materials yet discovered, meaning that they can be stretched and pulled a lot before breaking. This is mostly due to the nature of their chemical bonding (sp2) which is stronger than those of diamonds (sp3). They can also resist major pressure, have interesting (changing) electrical properties, show optical and EM absorption and good thermal conductivity. Too bad they also seem to be toxic if exposure is long enough.

Most applications of nanotubes, given their stiffness and strength, involve building very hard, but light structures (from vessel components to a hockey stick). However, despite its potential toxicity, there have indeed been some efforts to build bulletproof textiles with nanotubes. The key issue in this field is fiber spinning, which is actually feasible since 2000 (Paul Pascal Research Center in Pessac, France). Recent processes are based on the natural tendency of individual nanotubes to align themselves into ropes held together by van der Waals forces, so if some are pulled from a plane, others will try to realign with those. Ray H. Baughman of the University of Texas did the trick by driving a thread of aerogel into a nanotube substrate so that the stuff would align with the column (like a simplified Spidey alien suit!). Then, the aerogel is dissolved and, voila, you get a pure carbon membrane, light, flexible, ultrastrong and also an electrical conductor: super-light armor! Obviously, a suit of this stuff could stop bullets and knives, but there is still the problem of absorbing the strength: internal bleeding and broken bones would still be an issue.

Nanotube textiles have many other interesting applications, like heated fabrics, biosensing textiles or battery fabrics. Too bad nanotubes are still $1,000 per pound, right?