A plastic-based bolometer array sensor using carbon nanotubes for low-cost infrared imaging devices

• We propose a plastic-based bolometer array sensor for low-cost IR imaging.
• The CNT thin film thermistor of the sensor exhibited a TCR of −2.1%/K.
• Measured responsivity of 69 VB V/W (138 V/W at VB = 2.0 V) was obtained.
• Estimated NETD of 1.1 K was obtained on the basis of noise measurement.
• We confirmed the basic operation of IR imaging of a 64-pixel array sensor.

We have developed an infrared image sensor based on bolometers on a plastic substrate that is potentially ultra low-cost due to its simple structure consisting of mainly organic materials. The bolometer includes a thermal isolator made of a very low thermal conductive polymer (parylene) and a newly developed, highly sensitive (TCR <−2%/K) carbon nanotube thin film thermistor. Experiment results showed that the responsivity of our sensor was 138 V/W (at VB = 2 V) and the estimated noise equivalent temperature difference (NETD) at room temperature was 1.1 K. The row-column type 64-pixel (8 × 8) array sensor was fabricated and evaluated while the image of a heat source was focused on the sensor array by a Ge lens. Utilizing the test readout circuit based on switching modules, we obtained the images of the heat source and confirmed the basic operation of IR imaging.