MIT researchers are developing what they call "nano-origami," a technique for folding materials into tiny 3D structures with edges that are a hundred times thinner than a human hair. Someday, their work could lead to minuscule motors and components for faster microprocessors. Mechanical engineering professor George Barbastathis and his colleagues pattern the 2D shapes using conventional lithography technology. Then they use an external magnetic field, a beam of helium ions, or deposit metal on the materials' surface to induce the shape to fold itself up into a 3D structure. From the MIT News Office:
The folded shapes can be fabricated with a few different types of material, including silicon, silicon nitride (a type of ceramic) and a soft polymer known as SU-8."Engineers use 'nano-origami' to build tiny electronic devices"
Once the material is folded, the tricky part is getting the faces to align properly. The researchers have developed a few ways to do this successfully: one uses magnets; another involves attaching polymers to a certain spot on the faces and melting them with an electric current, sealing the two faces together.