Analyzing threshold pressure limitations in microfluidic transistors for self-regulated microfluidic circuits

Abstract

This paper reveals a critical limitation in the electro-hydraulic analogy between a microfluidic membrane-valve (mu MV) and an electronic transistor. Unlike typical transistors that have similar on and off threshold voltages, in hydraulic mu MVs, the threshold pressures for opening and closing are significantly different and can change, even for the same mu MVs depending on overall circuit design and operation conditions. We explain, in particular, how the negative values of the closing threshold pressures significantly constrain operation of even simple hydraulic mu MV circuits such as autonomously switching two-valve microfluidic oscillators. These understandings have significant implications in designing self-regulated microfluidic devices