A new wrist worn device called the Wristify recently won the 7th annual MADMEC competition held at the Massachusetts Institute of Technology. The device uses a miniature Peltier cooler which can be used to make you feel comfortable on a hot or a cold day using a thermoelectric effect.
You were probably told as a child, overheated from playing out in mid-summer, to put your wrists under a cold tap to help you quickly feel cool and comfortable. This effect works at the other extreme, say you have been out making a snowman in mid-winter, you can warm up quickly using hot/warm water on your wrists. Sam Shames, the MIT senior who helped invent the technology was in a room with his mother feeling uncomfortably warm, however his mother was cold - so he thought about this problem of who controls the thermostat. A physiology journal provided background information about how people experience temperature, from which he formulated the Wristify concept.
It’s a sensory illusion
The Wristify doesn’t just apply a constant heating or cooling source to the wrist. For example, to give a cooling feeling to the wearer the Wristify uses ‘pulse cooling’; cooling the wrist contact surface by 0.4 degrees Celsius once a second for 5 seconds then idling for the next 10 seconds. Due to our physiology this gives the wearer an overall body feeling of being a few degrees cooler.
Global warming etc
So the above explains the technology and how it works but to Sam Shames the idea is a lot bigger than making a few people feel a bit more comfortable in non-optimal ambient environments. He sees the Wristify partly as a solution to the huge amount of energy used in the USA in providing heating and air conditioning. Such activities account for nearly 17 per cent of the US total energy consumption. The Wristify can run for eight hours on a small lithium battery.
In the US 87 per cent of homes have air conditioning in contrast to Brazil (11 per cent) and India (2 per cent). Wristify could help cut the use of AC in the USA and people in those countries without the infrastructure to support AC in every house could live a lot more comfortably. Shames sums up by saying “Why heat or cool a building when you could heat or cool a person?”
Use it as the base for a smartwatch?
We are told that the Wristify prototype is made, in its present form, with about $50 worth of off-the-shelf parts. Shames says a device with the same effect could be made with about half the skin surface area used by the current version. I think this technology could be much more widely adopted if Apple, Samsung, Google or Microsoft smartwatches incorporated this copper Peltier base. An app could control the heating or cooling effect and act as a personal thermostat using an on-screen dial. That would be a really cool, or hot, smartwatch.
