Multi-element thermo-capillary optical switch and sub-nanoliter oil injection for its fabrication

To improve our previously proposed micromechanical optical switch based on the liquid flow induced by thermo-capillarity, in this paper we explain a new technique for injecting sub-nanoliter quantities of liquid that is necessary for thermo-capillary optical switches. To fabricate a multi-element switch, the oil must be encapsulated in all the switch elements uniformly and simultaneously. We have successfully demonstrated oil injection in a switch with eight elements that provides back-up sharing. The volume of the injected oil was 66/spl plusmn/6 pl. Switching was successfully performed in all switch elements.