Flexible Membrane Micro Flow-rate Threshold Flow Sensor

Abstract

A piezoresistive flow sensor that functions as a threshold flow switch, independent of input supply voltage, is designed, fabricated, and tested. The test flow rate is in the 10s ml/hr range. The sensor is fabricated using doped hydrogenated amorphous silicon thin film with MEMs on flexible polyimide substrate. The flow sensor is highly sensitive and able to distinguish between distilled water and 0.1 % NaCl saline solution in terms of threshold switch-on flow rate. The switch-on threshold of the flow sensor is observed to be independent of the applied input voltage. These turn-on threshold levels are adaptable to user’s application.

Keywords

• Flexible substrate
• Micro flow rate sensor