Journal Article

Adaptive infrared-reflecting systems inspired by cephalopods

Gorodetsky, Alon A., Stiubianu, George T., Xu, Chengyi

2018

Overview

Thermal vision cameras detect differences in temperature by sensing infrared wavelengths. If a coating could be developed that showed dynamic tuning of the effective temperature, it might be possible to hide objects from infrared sensing. Xu et al. started with a basic Bragg reflector made up of multiple layers of alternating materials with varying refractive index. The authors designed structures that were wavy to begin with so that they could be flattened out by electrical activation. This changed the infrared reflectivity and, thus, the effective temperature of the object observed in its infrared profile. Science , this issue p. 1495 Wrinkled multilayer structures underpin electrically actuated infrared-reflecting coating and display systems. Materials and systems that statically reflect radiation in the infrared region of the electromagnetic spectrum underpin the performance of many entrenched technologies, including building insulation, energy-conserving windows, spacecraft components, electronics shielding, container packaging, protective clothing, and camouflage platforms. The development of their adaptive variants, in which the infrared-reflecting properties dynamically change in response to external stimuli, has emerged as an important unmet scientific challenge. By drawing inspiration from cephalopod skin, we developed adaptive infrared-reflecting platforms that feature a simple actuation mechanism, low working temperature, tunable spectral range, weak angular dependence, fast response, stability to repeated cycling, amenability to patterning and multiplexing, autonomous operation, robust mechanical properties, and straightforward manufacturability. Our findings may open opportunities for infrared camouflage and other technologies that regulate infrared radiation.

• Publisher: The American Association for the Advancement of Science
• Subject: Actuation / Adaptive systems / Cameras / Camouflage / Cephalopods / Climate / Coating effects / Energy conservation / External stimuli / I.R. radiation / Infrared radiation / Insulation / Manufacturability / Mechanical properties / Multiplexing / Object recognition / Platforms / Protective clothing / Protective coatings / Refractivity / Skin / Spacecraft / Spacecraft components / Spacecraft shielding / Temperature effects / Wavelengths