Improvement of dynamic characteristics of polydimethylsiloxane based microvalve

Microfluidics is an indispensable part of micro total analysis system (mu-TAS) and lab-on-a-chip analysis systems. While most of the work in this area has focused on MEMS based actuation with micropumps and microvalves, polymer based Paraffin actuator is an attractive alternative in terms of ease in fabrication and low cost. While we made previous attempts in fabricating polydimethylsiloxane (PDMS) based devices, it suffered a drawback of low flow rates in the microchannel due to adherence of PDMS to the channel substratum. In the current work, we focused on improvement of mechanical properties of the PDMS membrane by altering prepolymer to crosslinker ratio. We found that a ratio of 100:15 produced sufficient tensile strength to the membrane and also enhanced actuation characteristics of microvalve fabricated with it