Membrane Light-Emitting Diode Flow Sensor

Multifunctional flow sensors are important components of smart systems when considering the Internet of things. In this work, a membrane light-emitting diode sensor (LED-S) is examined by utilizing the signals produced from the piezoelectric and heat dissipation effects for real-time flow rate detection. In association with silicon removal and backside III-nitride thinning, an InGaN/GaN LED is fabricated on a 1.58 mm diameter suspended membrane. In response to a flow rate change, the suspended membrane is deformed and the accumulated heat within the device is dissipated, which leads to an induced current. Consequently, the membrane LED can create light emission and flow detection simultaneously. The light emission is modulated for the implementation of visible light communication, which can connect the LED-S to the internet. These results demonstrate that the LED-S has great potential to be integrated into a multicomponent system for flow sensing, pressure sensing, and environment monitoring.