IIT Guwahati researchers develop self-cleaning, flexible heating fabric for cold climates

New Delhi, Feb 13 (PTI) Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a self-cleaning, flexible heating fabric for cold climates, which can mitigate health risks from prolonged exposure to extreme cold.

The findings of the research have been published in the journal Nano-Micro-Small.

According to Uttam Manna, Professor at the Department of Chemistry, IIT Guwahati, extreme cold temperatures can lead to health problems that may even be fatal.

"Studies indicate that deaths due to extreme cold outnumber those caused by extreme heat. Traditional solutions for protecting oneself from extreme cold, such as heaters or layered clothing, are often bulky or require a constant power source. Conductive textiles offer a lightweight, flexible alternative, but existing versions often have limitations, such as poor durability, high power consumption, and vulnerability to water exposure," Manna said.

To overcome these challenges, the IIT Guwahati research team developed a novel approach by spraying ultra-thin, clean silver nanowires onto cotton fabric to make it conductive.

"These nanowires are 100,000 times thinner than a human hair, allowing electricity to flow through the fabric, helping it generate heat while remaining soft and flexible. Due to its exceptional electrical conductivity and the ability to convert both electricity and sunlight into heat, silver nanowires were chosen for this experiment. The low electrical resistance of silver allows for electrothermal conversion at low applied voltage, eliminating the risk of electrocution," Manna added.

One limitation of silver nanowires is that they can tarnish over time, affecting performance. To address this, researchers applied a water-repellent coating to the silver nanowires that protects them against oxidation, water, and stains. The coating, inspired by lotus leaves, has a microscopic rough surface texture, which causes water to roll off instead of soaking in.

"This keeps the textile dry, ensuring long-lasting conductivity and effective heating, even in damp conditions. The water-repellent coating also prevents damage from sweat, rain, or accidental spills, making it reliable for outdoor and everyday applications. The textile can convert electricity using a small rechargeable battery or solar energy into heat and can maintain a desired temperature between 40-60 degrees Celsius for over 10 hours," Manna added.

The researchers tested the textile in wearable knee and elbow bands, demonstrating its potential to provide sustained warmth for individuals working in cold environments and for arthritis patients needing localized heat therapy.

"The textile has broader applications, such as on-demand water heating and accelerating chemical reactions by wrapping it around reaction vessels. Our textile is self-cleanable, breathable, and flexible and can easily be scaled up. Its durability and long-lasting performance make it useful in a range of applications that require controlled heating," Manna said.

The research team has filed an Indian patent on the innovation and is now working towards integrating the developed material with a miniaturised and appropriate electronic circuit to create viable products. PTI GJS GJS ARD ARD