A pressure cavity is durable, stable, and biocompatible and configured in such a way that it constitutes pico to nanoliter-scale volume. The pressure cavity is hermetically sealed from the exterior environment while maintaining the ability to communicate with other devices. Micromachined, hermetically-sealed...http://www.google.es/patents/US7854172?utm_source=gb-gplus-sharePatente US7854172 - Hermetic chamber with electrical feedthroughs
