Development of polysilicon devices for microfluidic thermal instrumentation

In microfluidics applications such as biology and chemistry, for which lab-on-chip and microreactors have been developed, the temperature control through a microchannel is of first interest. In this paper, we present a simple and generic technology for thermal sensing applications based on the fabrication of polysilicon diodes that can be implemented either on silicon, fused silica or silicon carbide substrates. Thermal sensitivities were characterized and as a first experimental approach a dedicated set-up was developed for the temperature measurement of a water flow through a SU-8 microchannel.

► We demonstrate the feasibility of a thermal sensor from a polysilicon diode. ► The polysilicon diode is used for microfluidic thermal instrumentation. ► The measured thermal sensitivity is −26.6 mV/°C for sensors on silicon. ► The fabrication process is transferred on silicon, fused silica or silicon carbide.