Shape memory polymer resonators as highly sensitive uncooled infrared detectors

作者：Ulas Adiyan, Tom Larsen, Juan Zarate, Luis Guillermo Villanueva, Herbert Shea · 发表于：Nature Communications · 年份：2019 · DOI：10.1038/s41467-019-12550-6 · 被引用次数：57 · 研究领域：Neurobiology and Insect Physiology Research、Advanced Sensor and Energy Harvesting Materials、Transition Metal Oxide Nanomaterials

Uncooled infrared detectors have enabled the rapid growth of thermal imaging applications. These detectors are predominantly bolometers, reading out a pixel's temperature change due to infrared radiation as a resistance change. Another uncooled sensing method is to transduce the infrared radiation into the frequency shift of a mechanical resonator. We present here highly sensitive resonant infrared sensors, based on thermo-responsive shape memory polymers. By exploiting the phase-change polymer as transduction mechanism, our approach provides 2 orders of magnitude improvement of the temperature coefficient of frequency. Noise equivalent temperature difference of 22 mK in vacuum and 112 mK in air are obtained using f/2 optics. The noise equivalent temperature difference is further improved to 6 mK in vacuum by using high-Q silicon nitride membranes as substrates for the shape memory polymers. This high performance in air eliminates the need for vacuum packaging, paving a path towards flexible non-hermetically sealed infrared sensors.