A THERMOPNEUMATIC VALVELESS MICROPUMP WITH PDMS-BASED NOZZLE/DIFFUSER STRUCTURE FOR MICROFLUIDIC SYSTEM

摘要

A thermopneumatic valveless micropump with a PDMS-based nozzle/diffuser structure was firstly designed and realized herein by stacking three layers of PDMS on a glass slide. Unlike the conventional peristaltic pumping configuration, the new structure of the micropump consists of only one set of heater on the glass slide, a thermopneumatic actuation chamber, and an actuation diaphragm. Additionally, it includes a flowing channel with nozzle/diffuser structure and inlet/outlet ports. In this valveless microchannel, fluid is driven by asymmetric flow resistance produced from the nozzle and diffuser configuration. The actuation diaphragm between the gas-pneumatic chamber and the flowing channel can bend up and down due to the gas expansion as well as the thermal buckling of the PDMS diaphragm imposed from the heating in the gas-pneumatic actuation chamber.