Design and Fabrication of Differential Scanning Nanocalorimeter for Biological Applications

Abstract

This paper describes the design, fabrication, and characterization of a differential scanning nanocalorimeter that has potential to significantly reduce the sample volume to microliter and improve the temperature sensitivity to 10 μK. The nanocalorimeter consists of a polymeric freestanding membrane, four high-sensitive low-noise thermistors based on the silicon carbide (SiC), and a platinum heater and temperature sensor. With the integrated heater and sensors, temperature scanning and power compensation can be achieved for calorimetric measurement. Temperature sensing SiC film was prepared by using sintered SiC target and DC magnetron sputtering under different gas pressure and sputtering power. The SiC sensing material is characterized through the measurement of current-voltage curves and noise levels. Thermal performance of a fabricated nanocalorimeter is studied in simulation and experiment. The results indicate the device has a nano watt thermal power sensitivity, 10 μK temperature sensitivity, and long time constant to hold thermal energy, which leads to low-volume ultra sensitive nanocalorimetry for biological process, such as protein folding and ligand binding.