Microelectromechanical systems, or MEMS, are small devices with huge potential. Typically made of components less than 100 microns in size — the diameter of a human hair — they have been used as tiny biological sensors, accelerometers, gyroscopes and actuators.

For the most part, existing MEMS devices are two-dimensional, with functional elements engineered on the surface of a chip. It was thought that operating in three dimensions — to detect acceleration, for example — would require complex manufacturing and costly merging of multiple devices in precise orientations.