Next-generation Miniaturized Thermal Imagers Based on Advanced Thermoelectric Materials and an Innovative Ultra-compact Optical Design

The proposed work promises to increase the sensitivity of JPL’s thermopiles by 5x. One of JPL’s most important product line instruments is the remote-sensing multi-spectral thermal imager (TI) using uncooled thermopiles arrays. Infrared remote sensing has a long history in planetary exploration, providing temperature and compositional information for the terrestrial planets and airless bodies, and probing the atmospheres of the giant planets and Mars. 

Our proposed miniaturized thermal imager will enable the next generation of JPL TI with a 5x greater sensitivity and a 2x larger field-of-view with a 2× larger filter block thus accommodating up to 2× more spectral channels embedded in an optical bench 2× smaller than an equivalent conventional design and with increased optical performance. This compact design will enable JPL thermal imagers to map scientific targets at higher resolution than ever before, with very high sensitivity in multiple spectral bands, and also make this miniature passively cooled instrument an attractive choice for future NASA missions to a broad range of planetary targets. Microbolometer arrays developed for night vision are commercially available and have been used on two space instruments (THEMIS on Mars Odyssey and the ISAR shuttle instrument) and under development to fly on the planned Europa Clipper mission (E-THEMIS). Microbolometers are intrinsically very sensitive to substrate temperature variation, making strict focal-plane temperature control essential. However, recent advances in electronics and materials allow microbolometer to operate at room-temperature with comparable performance with respect to JPL’s thermopiles. The goal of this work is to advance JPL’s thermopile program in order to be ahead of the competition.