The use of liquid rubber in micromachining focussed on flexible large area biocompatible membranes

This paper reports on a novel micromachining technique for fabricating rubber membranes with an area of tens of square centimetres and a thickness of a few micrometers. In the basic technique a silicon wafer is spincoated with liquid rubber, bonded to a second (sacrificial) wafer and locally thinned out by anisotropical wet etching. The potential of the technique is highlighted in a demonstration example where a 20 cm² large biocompatible membrane is used to mechanically support and thermally isolate a large active area thermopile in a microcalorimeter for medical use