If you live in a normal household chances are that there is constantly some bickering going on about the house being too cold or too hot. Now, thanks to an ingenious bracelet invented by the students from Cambridge based Massachusetts Institute of Technology (MIT), every household member can regulate his/her own body temperature and be perfectly comfortable.
Wristify is a thermoelectric bracelet that regulates the wearer’s body temperature by sporadically blasting his or her wrist with hot or cold pulses. Thermoelectric cooling is governed by the Peltier effect, which describes heating or cooling caused by electric current flowing across a junction of two different conductors. Basically, as current traverses these junctions, one side heats up while the other side cools down. If you have a series of these junctions, and put a heatsink on the hot side, you can create a very effective heat pump.
Peltier coolers aren’t efficient, but they do have the advantage of having no moving parts or circulating fluids. All you need is a Peltier heating/cooling element, a heatsink, and a battery. Throw in a wrist strap, and that’s exactly what the Wristify is. In India, where hot weather regularly causes huge, cascading blackouts, the power grid is so stressed that it couldn’t possibly accommodate more air conditioning. Wristify could significantly improve the quality of life for these people.