A Thermopneumatic-Actuated Polydimethylsiloxane Microfluidic System

In this paper, we have investigated the characteristics of a thermopneumatic-actuated polydimethylsiloxane (PDMS) microfluidic system integrated with a micropump and microvalves on the same structure. A thermopneumatic-actuated PDMS microfluidic system has been fabricated and its properties are characterized. The advantages of proposed microfluidic system are disposable, low cost fabrication process and transparent properties using indium tin oxide (ITO)-coated glass and PDMS. The flow rate of the proposed microfluidic system could be easily controlled by the switching function of the ITO heater. The flow rate of the microvalve gradually decreases as the applied heater power increase. At the membrane thickness of 350 mum, the power to cut-off flow is 400 mW. The optimized PDMS membrane thickness of 350 mum is acquired integrating a micropump and microvalve on the same substrate with the same fabrication process. The peak of the pumping rate in the micropump is observed at the duty ratio of 4% and frequency of 4 Hz for the applied pulse power. The maximum pumping rate is 70 nl/min