Fully disposable and optically transparent microfluidic viscometer based on electrofluidic pressure sensor

This paper reports a microfluidic viscometer with an embedded pressure sensor constructed using electrofluidic circuits, which are electrical circuits constructed by ionic liquid-filled microfluidic channels. The electrofluidic circuit provides a great pressure-sensing scheme with great long-term and thermal stability. The viscosity of the tested fluidic sample is estimated by its flow resistance, which is a function of pressure drop and flow rate, and the geometry of the microfluidic channel. The viscometer can be exploited to measure viscosity of either Newtonian or non-Newtonian power-law fluid under various temperatures. The developed sensor-integrated microfluidic viscometer is made of polydimethylsiloxane (PDMS) with transparent electrofluidic circuit makes it feasible to real-time monitor samples under tests. In addition, the entire device is fully disposable to prevent cross contamination between samples, which is desired for various chemical and biomedical applications.