A thermo-pneumatic in-channel microvalve with PDMS diaphragm for integrated blood examination system on silicon

In this paper, a thermo-pneumatic in-channel microvalve applicable to blood sample is presented. Thermo-pneumatic actuator with a drive chamber and a thermal expansion chamber is newly configured with backside pneumatic path. PDMS is employed as the diaphragm material for a long stroke actuation and adhesive layer between glass and silicon. Fabricated microvalves were evaluated with DI-water. Although hysteresis was observed when the microvalve is switched from close to open, the sealing performance of the closed microvalve was high enough thanks to the PDMS flexibility. This microvalve can be integrated in the blood examination system as its active fluid control devices.