By Topic

An electrostatically latching thermopneumatic microvalve with closed-loop position sensing

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
J. A. Potkay ; Eng. Res. Center for Wireless Integrated MicroSyst., Michigan Univ., Ann Arbor, MI, USA ; K. D. Wise

This paper presents a microvalve that combines thermopneumatic drive with an electrostatic hold, harnessing the advantages of both actuation mechanisms in a structure believed to be the first of its kind. A heater grid, elevated 10μm above the cavity floor, energizes a working fluid, raising the pressure in the cavity and deflecting the corrugated diaphragm and valve plate. A capacitive pressure sensor reads out the cavity pressure and valve seat position and provides feedback to determine when to apply the electrostatic hold voltage. Once latched, the power can be removed from the heater and, thus, the valve only requires power to transition from open to closed and consumes no static power. The thermopneumatic/electrostatic actuator combination provides high force, high speed, and low power in an 8×8mm die and is being developed for a low-power wireless gas chromatography system. The thermopneumatic actuator closes the valve in 1s at 200mW and the valve position is determined with a sensitivity of 4.3fF/Torr. The leak rate is less than 0.02sccm and the open flow is 3.3sccm at 130Torr. The electrostatic hold mechanism latches above 40V for thermopneumatic pressures greater than 600Torr.

Published in:

18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005.

Date of Conference:

30 Jan.-3 Feb. 2005