MEMS mechanical logic units: design and fabrication with micragem and polymumps

We are currently developing basic building blocks for creating digital logic units that are based on mechanical components, which could be used instead of transistors. Transistors, which are based on semiconductors, rely on precisely controlling the conductivity of their constituent materials. However, at low or high temperatures, that control is lost as semiconductors revert to intrinsic behaviour. Also, semiconductors exhibit various complications under ionizing irradiation. We are looking into creating logic units that use electrical signals, but mechanical relays, with technology provided by MEMS. The logic units consist of a mechanical relay with three electrical gates. The mechanical relay is fabricated with metal over insulator and is operated by applying voltage to the gate, which creates an electric force between the gate and a cantilever. The established electric force arches the cantilever, which is shorted to the source, to make a contact with the drain. Since the operation is based on interactions between metal gates, the proposed method does not suffer from the limitations shared by semiconductors. With different input combinations applied to the gates of the device, development of MEMS mechanical logic units is possible, including all of the standard digital gates.