2-way, reversible shape memory surfaces
Due to a phenomenon called theshape memory effect (SME), certain "memory metals" can be distorted andthen brought back to their original shape by a simple temperaturechange. While a one-way memory effect has inspired applications sincethe '60s, and a two-way memory effect can also make objects remembertwo different shapes, scientists have recently discovered that theeffect can now be realized at micro or nano scale on surface dentscan be turned into "mirrored" bumps.
A team of researchers from Michigan StateUniversity and General Motors, Yijun Zhang, Yang-Tse Cheng, and DavidGrummon, is pioneering two-way, reversible shape memory surfaces wheremicro- and nano-scale surface features can come and go as a result ofphase transformations in the materials structures.
While SME technology already surrounds us from bendable eyeglassframes and surgical tools to anti-scald faucets and fire sprinklersreversible SME will likely be exploited for an even wider range ofoptical, tribological (rubbing), and microelectromechanicalapplications. For instance, surfaces can become slippery or sticky bychanging temperature, or signs can appear and disappear by heating andcooling (see figure).
Source: physorg.comAdded: 28 September 2006