Formation of gears through buckling multilayered film-hydrogel structures

We investigate the buckling instability of a multilayered hydrogel tubular structure under shrinking using both analytical method and computer simulation. It is found that the mechanical stabilities enable three types of post-buckling configurations with regular patterns, that is, the formation of inner teeth alone, the formation of outer teeth alone, and the formation of both inner and outer teeth. The critical conditions and the post-buckling configurations have been predicted The controlled post-buckling structures may be used as basic building components for smart gear systems. (C) 2010 Elsevier B.V All rights reserved