Fabrication of a Micro Electromagnetic Flow Sensor for Micro Flow Rate Measurement

摘要

This paper presents the fabrication of a micro electromagnetic flow sensor for the liquid flow rate measurement. The micro electromagnetic flow sensor has some advantages such as a simple structure, no heat generation, a rapid response and no pressure loss. The principle of the micro electromagnetic flow sensor is based on Faraday's law. If conductive fluid passes through a magnetic field, the electromotive force is generatee and detected by two electrodes on the wall of the flow channel. The flow sensor consists of two permanent magnets and a silicon flow channelw ith two electrodes. The dimension of the flow sensor is 9 mm x 9 mm x 1 mm. The micro flow channel is mainly fabricated by anisotropic etching of two silicon wafers, and the detection electrodes are fabricated by metal evaporation process. The characteristic of the fabricated flow sensor is obtained experimentally. When the flow rates of water with the conductance of 100-200 muS/cm are 9.1 ml/min and 62 ml/min, the generated electromotive forces are 261 muV and 7.3 mV, respectvely.