A single-mask process for 3-D microstructure fabrication in glass and elastomers

This paper reports a novel technique to fabricate three-dimensional (3-D) out-of-plane structures in glass and in-plane structures in polydimethylsiloxane (PDMS). The fabrication technique and the transfer of desired patterns is based on a single-mask, single-etch process developed earlier [1, 2] to fabricate 3-D structures exploiting the Reactive Ion Etching (RIE) lag effects in silicon isotropic etching. Subsequently, patterns are transferred to glass and PDMS by the application of a series of anodic-bonding, glass re-flowing, and silicon etching processes. 3-D structures transferred to both glass and PDMS maintains the same aspect ratio and feature size of structures in silicon. This method enables the fabrication of round corners, semi-circular channels, and many other customized structures in both glass and PDMS.