Micro-object assembly with an optically addressed array

A microassembly system based on electric field manipulation is described. Optical addressing of a photo-transistor array controls the position and orientation of micro-objects using dielectrophoretic and electrophoretic forces. Open-loop control is used to rapidly direct many micro-objects in parallel. Closed-loop control is used to position micro-objects precisely. Demonstrations with beads (10 μm diameter) and silicon chips (150 μm scale) are presented. We have achieved coarse assembly at a rate of 1000 micro-objects per second, fine assembly of beads at micrometer scales, and arrays of silicon chips with orientation control. The technology aims to enable a generalized printer system for building engineered microstructure and electronics.