Surface micromachining and bulk micromachining are employed for realizing a porous membrane with bulk support for a microparticle fiter. The filter is sufficiently sturdy to allow for easy handling. It may be used as a diffusion barrier and under high pressures. The disclosed fabrication ...http://www.google.co.uk/patents/US5770076?utm_source=gb-gplus-sharePatent US5770076 - Micromachined capsules having porous membranes and bulk supports
