Micro flow sensor based on two closely spaced amperometric sensors.

In this communication, a novel micro flow sensor based on two closely spaced amperometric oxygen sensors is proposed and implemented. The simulation results show that the ratio of the responses of these two oxygen sensors is determined by flow rates in the micro-channel. The sensor has been implemented using a micro fabrication technique. The measurement results demonstrate that the technique is able to detect flow rates in the flow range of several microliters per minute when the distance between the working electrodes of two oxygen sensors is 10 microm and the cross-section of the micro-channel is 100 microm x 100 microm. The advantage of the proposed flow sensor is that no additional tracers have to be added or produced during the flow measurement. Information on dissolved oxygen concentration in the liquid is not required either.