Patterning: Three‐Dimensional Fabrication at Small Size Scales Small 7/2010

The cover image depicts a self-folding dodecahedron with embedded optical and electron microscopy images of self-folded structures. Self-folding overcomes the challenge of submillimeter-scale 3D patterning by transforming lithographically patterned 2D templates into 3D structures. The strategy is used to fabricate 100-nm- to 2-mm-sized polyhedra with a patterning resolution of 15 nm on all faces. Bidirectional hinges enable a hands-free origami approach for spontaneous folding of corrugated materials with thousands of patterned panels. Additionally, by utilizing hinges whose mechanical properties are altered by chemicals, microtools such as wireless grippers are constructed. Such microchemomechanical systems close and open when exposed to specific chemicals, without the need for any electrical power. For more information, please read the Review “Three-Dimensional Fabrication at Small Size Scales” by D. H. Gracias et al., beginning on page 792. Image credits: A. Zarafshar, T. Leong, N. Bassik, J. Cho, and D. Gracias.