Guwahati: Imagine a fabric that keeps you warm in freezing temperatures, runs on a tiny battery or just sunlight, and never gets soaked in the rain. Sounds futuristic? Scientists at IIT-Guwahati have made it a reality.
A research team at IIT-Guwahati has developed a self-cleaning, water-repellent, and electrically conductive textile that could revolutionize cold-weather clothing. Published in Small, the study details how this smart fabric generates heat using a low-power battery or weak sunlight—all while being lightweight, flexible, and completely waterproof.
The team, led by Prof. Uttam Manna from the Department of Chemistry, collaborated with researchers Debasmita Sarkar, Haydar Ali, Rajan Singh, Anirban Phukan, Chittaranjan Mishra, and Roy P. Paily from the Centre for Nanotechnology and the Department of Electronics and Electrical Engineering.
Extreme cold remains one of the leading causes of weather-related deaths globally. A recent study across 30 European countries found that cold temperatures accounted for an average of 130,228 deaths annually, nearly ten times more than heat-related fatalities. In countries like China, cold-related mortality follows a similar pattern. Exposure to severe cold can cause hemoconcentration-based arterial thrombosis, immune suppression, and bronchoconstriction, making effective thermal management essential.
Prof. Uttam Manna explained that electrically conductive textiles offer a promising way to address severe cold-related fatalities worldwide. However, existing materials face challenges like high operational voltage, short durability, and a lack of scalable fabrication.
The IIT-Guwahati team introduced a breathable, wrappable, and water-repellent conductive textile with electrothermal and photothermal conversion abilities. This ensures prolonged and efficient heating at low external voltage and weak sunlight, while a bio-inspired coating shields it from water damage and oxidation.
The innovation revolves around a special silver nanowire (AgNW) coating, which transforms ordinary cotton fabric into a highly conductive textile. When connected to a small battery, such as a power bank, the fabric’s temperature reaches up to 75°C using minimal energy.
When exposed to sunlight, the fabric heats up to 88°C, even on a cloudy day. Unlike conventional heated clothing, which loses effectiveness when wet, this fabric remains completely water-repellent. It also self-cleans, meaning dirt and dust slide off when rinsed with water. Prof. Manna explained that the team selected silver nanowires over non-metallic nanomaterials due to their superior electrical conductivity and inherent electrothermal and photothermal properties.
The water-repellent conductive textile protects the conductive layer from oxidation and moisture, maintaining superior heating performance compared to existing materials.
The textile is built with a two-layer design. A silver nanowire coating on cotton fabric ensures excellent electrical conductivity, while a bio-inspired superhydrophobic coating protects the material from oxidation, water exposure, and environmental damage.
This protective layer is inspired by nature—similar to lotus leaves, which repel water while remaining breathable. Tests showed that even acidic, alkaline, and detergent-contaminated water could not affect the material.
Moreover, even after 500 cycles of mechanical abrasion, including twisting, creasing, and rubbing, the fabric retained its conductivity and water-repellent properties. This makes it highly durable, unlike many other conductive textiles that degrade over time.
The team at IIT-Guwahati has successfully tested the fabric across multiple practical applications. It can be used in heated clothing such as jackets, gloves, and knee braces for arthritis patients. It is also suitable for battery-powered knee wraps for pain relief and muscle therapy.
Additionally, the fabric enables a unique “wrapped heating” method that speeds up the warming of drinks or accelerates chemical reactions. A knee brace embedded with this fabric maintained warmth for over 10 hours on a single charge. Prof. Manna stated that this technology can be applied in personal heat management, heat-assisted chemical reactions, and pain relief through thermotherapy.
The cost of producing this fabric in the lab is ₹23 per 100 cm², making it highly affordable for real-world applications once scaled for mass production. A patent has been filed, and researchers are hopeful that the technology will soon be available for workers, soldiers, and travelers in extremely cold climates.
The self-heating fabric isn’t just for warmth—it can also accelerate chemical reactions. Researchers tested the material by wrapping it around laboratory glassware, comparing wrapped heating to conventional surface heating.
The results showed a 100% improvement in reaction efficiency due to faster and more uniform heat transfer. One experiment involved a Mannich-type condensation reaction, where the new heating method increased the reaction yield by over 60% compared to conventional heating. The study noted that this heating method could be revolutionary for chemical processing, making industrial reactions more efficient and energy-saving.
Besides battery-powered heating, the fabric can trap and convert sunlight into heat. In field tests conducted in Guwahati, the fabric reached temperatures of 40°C in weak sunlight and 88°C in direct sunlight.
This means that in cold outdoor conditions, solar energy alone could provide warmth—ideal for soldiers, mountaineers, and outdoor workers. The study explains that this textile takes advantage of solar energy through a phenomenon called Localized Surface Plasmon Resonance (LSPR), where silver nanowires generate heat when exposed to light.
Another major innovation is self-cleaning. The researchers noted that outdoor textiles often accumulate dust, which reduces their efficiency, but the fabric’s hydrophobic layer ensures that dirt simply washes away with water. This guarantees consistent photothermal performance, unlike conventional fabrics that degrade when exposed to the environment.
The team is now looking at commercial production and further applications, including wearable heating technology for medical applications such as pain relief and muscle therapy, on-demand heating for drinking water in cold environments, military and extreme cold-weather gear for soldiers, and integration with smart fabrics for next-generation wearable technology. With a low-cost, durable, and scalable production process, this self-cleaning fabric could revolutionize winter wear and personal heating solutions.
Would you trade your bulky winter gear for this futuristic smart fabric?
Also Read: For generations, they fished: Now, Assam fishermen catch microplastics