When temperatures soar, most of us reach for the air conditioning. But what about those who can't escape the heat? Firefighters battling infernos, construction workers toiling under the midday sun, and factory staff facing furnace-like conditions have long struggled with bulky, stifling protective gear. This issue is becoming increasingly critical. According to the World Health Organization, globally, there were approximately 489,000 heat-related deaths annually between 2000 and 2019, with 45% occurring in Asia and 36% in Europe.

Now, a first-of-its-kind innovation from Dr Dahua Shou, Limin Endowed Young Scholar in Advanced Textiles Technologies and Associate Professor of the School of Fashion and Textiles, and his team promises to change the game. They have developed “intelligent” thermally-insulated and breathable soft robotic clothing that automatically adapts to changing temperatures. Their research findings have been published in the international interdisciplinary journal Advanced Science.

Drawing inspiration from the adaptive thermal regulation mechanism of pigeons, Dr Shou’s team has created a textile that mimics nature’s ingenuity. Just as pigeons use their feathers to trap a layer of air surrounding their skin to reduce heat loss to the environment, this unique soft robotic textile employs soft actuators to create an adjustable air gap, enhancing thermal resistance in response to temperature changes.

The science behind the fabric

At the heart of this innovation lies soft actuators strategically embedded within the clothing. These actuators, designed like a human network-patterned exoskeleton-like, contain a non-toxic, non-flammable fluid with a low boiling point. As ambient temperatures rise, the thermos-stimulated system turns the fluid from a liquid into a gas, expanding the actuators and thickening the textile matrix. This clever mechanism doubles the thermal resistance from 0.23 to 0.48 Km²/W, providing superior insulation against heat.

Unlike traditional protective gear with fixed thermal resistance, this soft robotic clothing offers dynamic temperature adaptation. It can maintain inner surface temperatures at least 10°C cooler than conventional heat-resistant clothing, even when the outer surface reaches a scorching 120°C. The material’s porous, spaced knitting structure also ensures high moisture breathability while reducing convective heat transfer.

Made from thermoplastic polyurethane, the textile is soft, resilient, and durable. It has passed rigorous washing tests without leakage, proving its practicality for everyday use. What’s more, this innovative clothing regulates temperature without relying on energy-consuming technologies like thermoelectric chips or liquid cooling systems.

A cool future

Dr Shou envisions a wide range of applications for this technology, from activewear and winter jackets to healthcare apparel and sustainable textile-based insulation for construction and buildings, contributing to energy-saving efforts. With support from the Innovation and Technology Commission and the Hong Kong Research Institute of Textiles and Apparel, his team is already expanding the thermos-adaptive concept to develop inflatable, breathable jackets and warm clothing for low-temperature environments.

Reflecting on the innovation’s inspiration, Dr Shou pointed to the extreme conditions faced by firefighters. “Seeing them emerge from fire scenes with boots filled with sweat highlighted the urgent need for better thermal management in protective gear,” he explained. “This motivated me to develop a novel suit adapting to various temperatures while maintaining excellent breathability.” Dr Shou emphasised that their soft robotic clothing “can seamlessly adjust to different climates and working conditions, ensuring constant thermal comfort under intense heat".

As global warming intensifies, this soft robotic clothing offers a promising solution. Its ability to adapt to various conditions could significantly improve thermal comfort and safety across industries, from firefighting to construction, potentially transforming worker protection in challenging environments.