Journal of Fluid Mechanics



Mass flow and tangential momentum accommodation in silicon micromachined channels


ERROL B. ARKILIC a1, KENNETH S. BREUER a2 and MARTIN A. SCHMIDT a3
a1 Phasyn, San Carlos, CA 94070, USA
a2 Division of Engineering, Brown University, Providence RI 02912, USA
a3 Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, MA 02139, USA

Abstract

High-precision experimental results are reported showing the tangential momentum accommodation coefficient (TMAC) for several gases in contact with single-crystal silicon to be less than unity. A precise and robust experimental platform is demonstrated for measurement of mass flows through silicon micromachined channels due to an imposed pressure gradient. Analytic expressions for isothermal Maxwellian slip flows through long channels are used to determine the TMAC at a variety of Knudsen numbers. Results from experiments using nitrogen, argon and carbon dioxide are presented. For all three gases the TMAC is found to be lower than one, ranging from 0.75 to 0.85.

(Received October 4 1999)
(Revised December 18 2000)



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