A dual-mode textile for human body radiative heating and cooling

TLDR

Maintaining human body temperature requires significant energy, and recent work has shown that heating and cooling textiles can extend the ambient temperature range by controlling infrared radiation, but achieving both functions in a single textile remains a challenge. This study aims to demonstrate a dual‑mode textile capable of passive radiative heating and cooling without external energy input. The textile consists of a bilayer emitter embedded within an infrared‑transparent nanoporous polyethylene layer, enabling asymmetric emissivity and thickness to switch between heating and cooling modes. The dual‑mode design achieves a 6.5 °C expansion of the thermal comfort zone, with numerical modeling predicting up to 14.7 °C for textiles with larger emissivity contrast.

Abstract

Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement. We demonstrate a dual-mode textile that can perform both passive radiative heating and cooling using the same piece of textile without any energy input. The dual-mode textile is composed of a bilayer emitter embedded inside an infrared-transparent nanoporous polyethylene (nanoPE) layer. We demonstrate that the asymmetrical characteristics of both emissivity and nanoPE thickness can result in two different heat transfer coefficients and achieve heating when the low-emissivity layer is facing outside and cooling by wearing the textile inside out when the high-emissivity layer is facing outside. This can expand the thermal comfort zone by 6.5°C. Numerical fitting of the data further predicts 14.7°C of comfort zone expansion for dual-mode textiles with large emissivity contrast.