Flexible infrared camouflage eutectic gallium-indium for thermoelectric energy harvesting.

Abstract

Integrated infrared camouflage materials capable of energy harvesting and sensing hold great potential for enhancing operational efficiency in military settings. A key challenge, however, lies in achieving such multifunctionality without complex fabrication processes. In this study, we address this issue by introducing eutectic gallium‑indium (EGaIn) as a versatile material that combines infrared camouflage with thermoelectric sensing. EGaIn exhibits remarkable infrared camouflage performance over a broad temperature range. It suppresses its own thermal radiation by reflecting ambient infrared radiation, concealing its infrared signature for infrared camouflage. In addition to its infrared camouflage function, one of the most notable features of EGaIn is its ability to generate voltage from small temperature gradients. This thermoelectric capability enables self‑powered, real‑time monitoring of physiological states like body temperature and breathing patterns. Our work highlights the pathways toward military technologies that combine infrared camouflage with signal transmission capabilities.