Measurement of Temperature in Parallel Channel of Microfluidic Reactors

Measurement of temperature in microfluidic devices during their operation is a common and important task. Knowledge of the temperature value, steepness of the temperature gradient, or temperature evolution over time is crucial for subsequent modelling or control of chemical processes taking place inside the device. However, due to spatial limitations, the integration of sensors can be very challenging. Herein, the development of a temperature monitoring system integrated into a flexible polydimethylsiloxane (PDMS) based microfluidic reactor is presented for use in electrochemical flow cells. The system is based on a set of thermistors mounted in one of the parallel channels of the multichannel microfluidic reactor. Sacrificing one of the channels allows the integration of inexpensive and relatively large sensors into the device and the measurement of the temperature directly inside the electrochemical system even under harsh conditions. The static and dynamic properties of the system are evaluated. Furthermore, the fabricated system can be easily integrated into the standard manufacturing process of any microfluidic device.