Development of a Novel MEMS Gas Flowmeter with a Temperature Difference Suspension Structure

Micro-electro-mechanical system (MEMS) gas flowmeters are innovative devices that use microfabrication technology to measure gas flow with high precision and sensitivity. With MEMS technology, flow measurement can now be performed more accurately and compactly than ever, using low-power, compact, and highly accurate sensors. MEMS gas flowmeters utilize various principles to measure gas flow, including thermal, Coriolis, and pressure differential methods. A micro-flowmeter was developed by combining a MEMS sensor with a weak signal acquisition technique. High heat isolation and sensitivity can be achieved using a MEMS sensor with a thermal resistor-suspended VO2 structure. Since SU-8 gum is used for the flow channel, the technology is simple and affordable, making it suitable for batch production. To acquire high-resolution, low-noise data, the device uses a super low bias current operational amplifier, aided by guard ring protection, and a 24-bit high-resolution ADC. The sensor and data acquisition combination shows that the flowmeter has favorable linearity and sensitivity between 0 and 50 mL/min at a specific offset voltage. Biochemical detection and medicine require a high-sensitivity, high-stability, and low-cost flowmeter.