Valve-only pumping in mechanical gas micropumps

This paper introduces a new class of compact, highly scalable and efficient membrane-based gas micropumps in which both stroke and flow-control actions are realized by checkerboard microvalves. Realized based on a novel scalable and modular microfabrication technology, the micropump reported here utilizes an unwanted secondary pumping effect, valve pumping, as the main pumping principle, eliminating the need for any pumping membrane. This reduces down the entire pumping structure to a collection of active microvalves, and hence, significantly simplifies the configuration and operation of mechanical gas micropumps and minimizes their dead volume (often the Achilles heel for gas micropumps). Valve-only pumping can produce a flow rate as high as 160 μL/min using only two valve membranes and pressure accumulations of 500 Pa, for a 4-stage device, while it also improves the total device size by 50%.