Researchers from the National Microelectronics Research Centre (NMRC) in Ireland have used electric fields to direct arrays of gallium arsenide light-emitting diodes to assemble onto silicon chips.

The researchers’ self-assembly device contains an array of electrodes on a silicon surface that allows them to put electric fields of specific configurations on the surface of the chip. The fields can be configured to attract electric charges at a particular spot and repel it everywhere else. The right configuration causes components to rapidly move from one spot to another. Once the components are in place, the transport fluid is evaporated and the components fused to the surface by melting and cooling the chip’s tin-gold contacts.

The method is scalable down to the nano level, and could eventually be used to assemble nanoelectronic, nanophotonic, and nanoscale biotechnology devices. It could be used practically in two to five years.