A SiN Microcalorimeter and a Non-Contact Precision Method of Temperature Calibration

A dual-channel flow-through microcalorimeter device is presented along with a non-contact precision method of temperature calibration. A microfluidic channel with a volume of approximate to 550 pL in a spiral layout was fabricated from low-stress nitride suspended over a cavity in a silicon substrate. The thin-film heater and resistive temperature detector (RTD) on the channel were defined by a patterned Ti layer. The device exhibited a rapid thermal response with the following thermal characteristics: a time constant of approximate to 10.5 ms, a heat conductance of approximate to 152 mu W. K-1 and a heat capacitance of approximate to 1.6 mu J . K-1 on average based on the measurements of nine separate units fabricated on the same wafer. Further, the melting curve analysis (MCA) of a double-stranded DNA was proposed as a non-contact method of microcalorimeter RTD calibration. The method revealed that the measurement by the RTD underestimates the temperature of the channel interior by an amount of nearly 15%, at approximate to 9 mW. At this dissipated power level, the method also revealed a spatial nonuniformity of approximate to +/- 0.8 degrees C across the microcalorimeter. [2020-0173]