Flexible passive radiative cooling inspired by Saharan silver ants

Saharan silver ants can inhabit one of the hottest areas, the Sahara Desert, which benefits from their thermoregulatory functionality, thanks to a sophisticated photonic structure of hairs. Mimicking the photonic structure, we fabricated the flexible hair-like photonic structures on polydimethylsiloxane (PDMS). Attaching them to glass bottles for a proof-of-concept demonstration, the considerably enhanced optical reflection was observed as well as the slightly improved mid-infrared emission. These extraordinary properties enabled the temperature of the glass bottles to be reduced by around 5.6 °C in the hot daytime and keep relatively warm in the cold nighttime. On the basis of optical and thermal properties of the silver ants-inspired photonic structures, potential applications could be further found in wearable devices and personal thermal management. •We mimicked the Saharan silver ants' hair and fabricated the biomimetic structures.•The biomimetic structures exhibited the improved optical reflection and heat dissipation as silver ants.•The temperatures of glass bottles, covered by the biomimetic structures, were reduced by 5.6 °C in the hot daytime.•The glass bottles did not exhibit the considerable heat loss in the cold nighttime.•The flexible biomimetic structures could be applied in wearable devices and personal thermal management.