Uncooled long-wavelength infrared sensor using cytochrome c protein on CMOS read-out circuits

Cytochrome c protein thin film shows high temperature coefficient of resistance (TCR). In this paper, we studied the characteristics of cytochrome c protein, whose absorption rate is 65% at wavelengths of 10 μm. We designed a chip for an infrared microbolometer with suspended aluminum electrodes. The protein solution was deposited on a sensing pixel using an inkjet printer. The TCR, thermal conductance, time constant, responsivity and detectivity were 25.98(%/K), 7.96 × 10^-5 (W/K), 1.094 (ms), 2.57 × 10⁴ (V/W) and 5.89 × 10⁸ (cm · Hz^1/2/W), respectively. We experimentally demonstrated integrating cytochrome c protein with a CMOS circuit as a sensing pixel for a long-wavelength infrared microbolometer at room temperature. Based on our experimental results, such a microbolometer array holds promise for the future.