Aerogel ribbons drawn from forests of carbon nanotubes can act spectacularly as an artificial muscle of sorts. Ali Aliev and colleagues of the University of Texas at Dallas have created the material that, in response to an applied voltage, rapidly and reversibly triples in width and thickness while contracting in length.
With the strength and stiffness of steel in one direction and more flexibility than rubber in the other two, such ribbons can operate over temperatures ranging from that of liquid nitrogen to the melting point of iron. Perhaps even more remarkable, the ribbons are optically transparent.