Fig. 4

Mechanical modulation of the narrowband reflectance. a The change in the surface morphology and the reflection of infrared light of a TiO₂/SiO₂ Bragg stack-modified structures before mechanical actuation. b After mechanical actuation. c The infrared reflectance spectra of a TiO₂/SiO₂ Bragg stack-modified structures with a peak reflectance intensity at 5 μm before mechanical actuation. The total reflectance (red traces) are shown along with their reflection (black traces) and diffuse (blue traces) components. d After mechanical actuation. e The infrared spectra of three unactuated devices that have been designed to feature peak reflectance wavelengths of 3 μm (red trace), 4 μm (blue trace), and 5 μm (black trace). f Plots of the total, reflection, and diffuse peak reflectance of the TiO₂/SiO₂ Bragg stack-modified structures as functions of the applied length strain