Reduction of Microvalve Leakage based on Precise Measurement of Flow Conductance

Abstract

This paper reports a reduction of microvalve leakage according to precise measurements of the leak and flow rates. The tight contact between a valve cap and seat, which is obtained by nanometer-scale flat surfaces and by self-alignment of a cap and seat-bore, makes the leakage from a microvalve ultra-low. The leak and flow rates are determined by precisely measuring pressure changes when introducing helium gas into a flow line. We have, consequently, attained a leak rate as low as 5.8×10^-10Pa⋅m³/s and a flow rate ranging from 5.8×10^-10 to 3.2×10^-4Pa⋅m³/s.