Hi-Tech Fabric Provides Wearable Heater

By Julianne Glaser

Since the dawn of mankind, keeping warm during the cold winters has been priority. Now, scientists have created an innovative fabric that traps body heat and may eventually provide a cost-effective means to keep you warm and toasty in cold temperatures without turning up the thermostat.

The Future of Warmth

Researchers from Stanford University led by Yi Cui have transformed ordinary cotton fabric into a wearable "mini heater" that reflects the wearer's heat, or infrared radiation, back to the body. The team created a mesh of easily bendable nanowire coated with silver that's placed on top of the fabric. As reported in Nano Letters, the fabric mesh can trap nearly 80 percent of the body's heat while the nanowires' porous structure allows moisture to pass freely, maintaining the fabric's breathability and the wearer's comfort.



Nanowire Coated with Silver

Additionally, the silver nanowire structure creates a conductive network throughout the cloth that increases warmth when exposed to micro amounts of electricity, such as working at a computer. Silver has the highest electrical conductivity of all metals, so movement of electricity across the cloth from an electrical device effectively creates Joules heating. In fact, just 0.9 volts of electricity can warm the cloth to a 100 degrees Fahrenheit.

Moreover, according to Cui, the high-tech fabric is relatively inexpensive to produce — about one dollar's worth of silver is all that's needed to cover clothing for the entire body, except for head and hands.

Safety testing is ongoing to determine any potential human health effects with silver nanowire, and the fabric is likely years from commercial availability. With heating costs on the rise, this personal thermal management fabric might be the next major development in cost-effective and environmentally safe heating. Meanwhile Cui and his team are looking to develop a similar silver-coated nanowire fabric to keep the body cool.

Extension Questions

  • What would be some possible safety concerns with this nanowire thermal clothing?
  • What are other energy-efficient ways to cut heating costs?