document: Surface micromachined paraffin-actuated microvalve Normally-open microvalves have been fabricated and tested which use a paraffin microactuator as the active element . The entire structure with nominal dimension of phi 600 mu m * 30 mu m is batch-fabricated by surface micromachining the actuator and channel materials on top of a single substrate . Gas flow rates in the 0.01-0 .1 sccm range have been measured for several devices with actuation powers ranging from 50 to 150 mW on glass substrates . Leak rates as low as 500 mu sccm have been measured . The normally-open blocking microvalve structure has been used to fabricate a precision flow control system of microvalves consisting of four blocking valve structures . The control valve is designed to operate over a 0.01-5 .0 sccm flow range at a differential pressure of 800 torr . Flow rates ranging from 0.02 to 4.996 sccm have been measured . Leak rates as low as 3.2 msccm for the four valve system have been measured
doc_bio_tags: O O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I I O O O O O O O O O O O O O B I O O B I I I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O B I O B I O B I O O O O O O O O O O B I O O O O O O O O O O O O O
extractive_keyphrases: paraffin microactuator active element channel materials gas flow rates actuation powers leak rates blocking valve structures differential pressure flow rates 50 to 150 mw 800 torr
abstractive_keyphrases: surface micromachined microvalve normally-open microvalves 600 micron 30 micron