Nanotube Velcro

Joining two or more nanochips, such as nano-electromechanical systems (NEMS), can be done by welding or gluing or with tiny nuts and bolts. But what if you could gently just fasten them the way fabrics are fastened, with velcro? Conventional velcro fastening works by pairing one patch of mm-scale hooked protuberances with a patch of looped protuberances. In the microscopic version, both patches would bristle with carbon nanotubes, grown upright except for a hook on the top end. David Tomanek and his colleagues at Michigan State (517-355-9702) are studying how to make nano-velcro work (see movies). His calculations so far show that the nanotubes will remain in place on each separate substrate (they can be grown on selective pieces of surface geometry using lithographic-like patterning techniques) and will also remain locked together when mated with its counterpart on another substrate. A typical application for nano-velcro would be to fasten a diamond coating onto specific parts of a metal surface. (Berber et al., Physical Review Letters, upcoming article; co-authors, Savas Berber, and Young-Kyun Kwon)