Shape memory polymer resonators as highly sensitive uncooled infrared detectors.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31586068.
- Also identified by DOI 10.1038/s41467-019-12550-6 and PMC identifier 6778134.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
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.