Turning up the heat

The Smart Textiles Innovation Centre at Canesis in New Zealand is developing a range of battery-powered blankets and heated socks.

With the support of Australian Wool Innovation Ltd (AWI), the Smart Textiles Innovation Centre at Canesis in New Zealand is developing a range of novel heated wool textiles.

To do so, they combine electrically conductive fibres with wool, creating textiles that radiate a uniform, gentle heat. Science Manager, Stewart Collie, says that apart from discreet electrical connectors, the textiles look and feel like conventional ones, even with close inspection – until, of course, they are switched on.

The supply of electricity to the heated textile is obviously an important technological issue, and while products to be used in the home can simply be connected to the mains supply, the challenge for wearable systems is to be able to supply useful heat without the need to carry cumbersome battery packs.

“We’re using the newest, lightweight, high-output rechargeable batteries for portable applications, and getting good heating for several hours,” Stewart says.

One application, which is well advanced, is heated blankets, which are safer than conventional electric blankets, as they can operate from a low voltage; that means that even if a glass of water is spilt on the blanket, there is little chance of short circuiting and none of electrocution. Similarly, because there are no hard wires within the blanket, it can be safely folded and stored, unlike conventional electric blankets.

Also moving beyond the prototype stage is a battery powered heated sock, which can be switched on and off to prolong the active heating time, currently about three hours if used continuously.

Stuart McCullough, AWI Manager of product commercialisation, says the company is keen to explore a joint venture product for the skiing and snowboarding market, where the socks could be powered by a rechargeable battery incorporated into the sole of a boot.