Uncooled Long-Wavelength Infrared Sensors Using Cytochrome C Protein on Suspension Electrodes With CMOS Readout Circuits

We systematically investigate the characteristics of cytochrome c protein, whose absorption rate is 65% at wavelengths of $10~\mu \text{m}$ . We design a chip for an infrared sensor with suspended aluminum electrodes. The protein solution is deposited on sensing pixels using an inkjet printer. The temperature coefficient of resistance, responsivity, 1/f noise, and noise equivalent temperature difference are 29 %/K, 1.5*10⁵ V/W, 5.88*10⁻⁵ V/Hz^1/2 at 1.78 Hz and 4.29 mK, respectively. Cytochrome c protein thin film, possessing a high-temperature coefficient of resistance, is suitable for microbolometer design. We experimentally demonstrate integrating cytochrome c protein with a CMOS circuit as a sensing pixel for a long-wavelength infrared microbolometer at room temperature.