Towards high-speed imaging of infrared photons with bio-inspired nanoarchitectures

Existing infrared detectors rely on complex microfabrication and thermal management methods. Here, we report an attractive platform of low-thermal-mass resonators inspired by the architectures of iridescent Morpho butterfly scales. In these resonators, the optical cavity is modulated by its thermal expansion and refractive index change, resulting in 'wavelength conversion' of mid-wave infrared (3-8 mu m) radiation into visible iridescence changes. By doping Morpho butterfly scales with single-walled carbon nanotubes, we achieved mid-wave infrared detection with 18-62 mK noise-equivalent temperature difference and 35-40 Hz heat-sink-free response speed. The nanoscale pitch and the extremely small thermal mass of individual 'pixels' promise significant improvements over existing detectors. Computational analysis explains the origin of this thermal response and guides future conceptually new bio-inspired thermal imaging sensor designs.