Fabric-inspired thermoelectric two-dimensional imaging array based on carbon nanotube

Abstract

A thermal imaging array can be a convenient tool for health monitoring and security applications. In this work, a two-dimensional wearable thermal imaging sensor array design comprised of the carbon nanotube (CNT) harnessing thermoelectric effect is proposed. The proposed sensor device was constructed of an array of p-type CNT fibers that are woven across another array of n-type CNT fibers in the similar manner fibers that are woven in textile fabric. Electromagnetic (EM) wave emitted from the subject of detection increases the temperature of certain array nodes of the sensor device, which causes voltage differences between different p–n fiber junctions. Mapping the voltages of all the p–n junctions, thermal images of the subject can be obtained. Though there is a trade-off between responsivity and detection resolution, our proposed sensor can provide a responsivity of 57 V/W for a nanowatt range EM power source with submicrometer level detection resolution according to our calculation. Moreover, we theoretically investigated the effect of the junction distance in the sensor and the size of the hotspot on the resultant thermoelectric voltage.