Temperature and flow rate measurements with FBG sensors embedded in microfluidic devices

This paper proposed a temperature and flow rate dual-parameter sensor based on fiber Bragg grating embedded in microfluidic chips. The medical grade biocompatible tapes were cut into designed shape by femtosecond laser and then stacked layer by layer to form the microfluidic chip. Two FBG sensors were embedded near the fluid channel. When liquid was pumped into the microfluidic chip, the tape deformed due to pressure and squeezed the FBG sensor above. The flow rate can be obtained based on the FBG center wavelength shift. The temperature sensor is only sensitive to temperature, thereby compensating for the temperature influence of the flow sensor. The experimental results show that the dual-parameter sensor can accurately measure the temperature and flow rate with a sensitivity of 0.2°C and 50 μL/min.