Wednesday, August 28, 2013
PBS NOVA: Pogue demonstrates making materials into shape-shifters (the spiderman gecko)
Some PBS stations re-aired the 2011 NOVA episode “Making Stuff Smarter” with David Pogue. The basic video link is here.
A lot of it was surprising. Many substances behave surprisingly because of physical surface features at a micro level.
An early demonstration was that of the “spiderman lizard”, the gecko. The bottoms of its feet have tiny hairs which, being so small, invoke “Van der Waals forces” that grip and release at will. In the animal world, “thmooth” isn’t always “desirable.”
Pogue showed how a military tank can be coated with a surface that can seal bullet holes automatically by reacting with the fuel
He then demonstrated “non-Newtonian” fluids, with variable (and often high) viscosity. An example is “ooglex” (a particular cornstarch in water) which hardens during sudden trauma but the flows. He also demonstrated an “X-men” magnetic liquid which hardens only when there is a magnetic field.
Pogue then showed how aircraft wings can be made of material that can change internal shape automatically.
He also showed unusual research in preventing side effects from cancer chemotherapy.