Miniaturization of pinch-type valves and pumps for practical micro total analysis system integration

In this paper, to address the issues relevant to leakage, dead volume and contamination, we have miniaturized a pinch-type valve and a pinch-type peristaltic pump, which are surface mountable on the microfluidic lab-on-a-chip (LOC) devices. The pinch-type valve consisted of a solenoid magnetic actuator with a pinch plunger and a biomedical grade silicone tube. The pinch valve has shown excellent characteristics of no detectable leakage flow up to 200 kPa and zero dead volume, keeping its surface mountable capability over the microfluidic devices. Furthermore, the new pinch-type peristaltic pump realized by connecting three pinch-type valves in series has shown self-priming and bi-directional pumping capabilities. The pump enabled a wide pumping rate control over 33:1 from 30 νl min^-1 at 0.4 Hz up to 1000 νl min^-1 at 100 Hz. Back pressure of the pump was 280 cm of water pressure at 20 Hz, equivalent to 27.6 kPa. As a result, the miniaturized stand-alone pinch-type valve and pump developed in this work will have many practical applications in miniaturized total analysis systems (μ-TAS).