Fold-your-own flower. A new technique folds simple sub-millimeter shapes from sheets of rubber using only the force of surface tension from a drop of water.
Image Credit: Phys. Rev. Lett. 98, 156103 (2007)
When you dry your hands after washing them they don’t typically warp and wrinkle. That’s not the same with paper. Water ruins books, math homework and origami cranes. However, researchers at the Institute of Industrial Physics and Chemistry (ESPCI) in Paris and cut geometric shapes a millimeter or so across from thin, rubbery membranes ranging from 40 to 80 millionths of a meter thick. They then placed a drop of water large enough to reach all corners on top of each shape. As the liquid evaporated, its surface tension tugged the membrane closer around the water's decreasing volume, until the remaining liquid was completely encapsulated inside a sphere, tetrahedron, or some other shape.
This demonstration could lead to improved techniques for constructing microscale or even nanoscale objects by starting with flat pieces that are easy to cut and mass produce.