Wearables

Wristify thermoelectric bracelet makes heating and cooling personal

Wristify thermoelectric bracel...
The Wristify thermoelectric bracelet being put to the test at MIT's MADMEC (Photo: Franklin Hobbs)
The Wristify thermoelectric bracelet being put to the test at MIT's MADMEC (Photo: Franklin Hobbs)
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The Wristify thermoelectric bracelet being put to the test at MIT's MADMEC (Photo: Franklin Hobbs)
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The Wristify thermoelectric bracelet being put to the test at MIT's MADMEC (Photo: Franklin Hobbs)
Wristify uses a copper heatsink to heat or cool the skin on the wrist, which can affect the thermal comfort of the entire body
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Wristify uses a copper heatsink to heat or cool the skin on the wrist, which can affect the thermal comfort of the entire body

Most bracelets aren't likely to alter your temperature too much either way, but the Wristify isn't most bracelets. Developed by four MIT engineering students, the Wristify works on the principle that heating or cooling the skin on one part of the body can make the entire body feel warmer or colder. By creating a personal heating and cooling device, the Wristify team ultimately hopes to cut the amount of energy currently used to heat or cool entire buildings.

Currently at working prototype stage, the Wristify resembles a wristwatch with a custom copper-alloy-based heat sink. This is is attached to an automated control system that automatically adjusts the intensity and duration of thermal pulses that are delivered to the heat sink based on readings from thermometers integrated into the device that measure external and body temperature. The prototype can run for up to eight hours thanks to a lithium polymer battery.

While developing Wristify, the team found that minute, rapid changes in temperature on one part of the human body can affect the whole body. They discovered that a change of 0.1° C (0.18° F) a second is the minimum rate required to make the entire body feel several degrees warmer or colder. The current prototype, which is the team's 15th, is capable of a rate of change of up to 0.4° C (0.7° F) per second.

Wristify uses a copper heatsink to heat or cool the skin on the wrist, which can affect the thermal comfort of the entire body
Wristify uses a copper heatsink to heat or cool the skin on the wrist, which can affect the thermal comfort of the entire body

The team believes that by providing individuals with a personal cooling and heating device, the Wristify has the potential to cut the amount of energy currently used to cool and heat the space within buildings. They say that adjusting the temperature of just one building by 1° C (1.8° F) can consume around 100 kWh per month, so while the device won't be able to completely replace a building's heating and cooling system, it could allow for significant savings.

“Buildings right now use an incredible amount of energy just in space heating and cooling. In fact, all together this makes up 16.5 percent of all US primary energy consumption. We wanted to reduce that number, while maintaining individual thermal comfort,” says Sam Shames, who co-invented the Wristify with Mike Gibson, David Cohen-Tanugi, and Matt Smith. “We found the best way to do it was local heating and cooling of parts of the body.”

The team recently took out the US$10,000 first prize in MIT's annual Making And Designing Materials Engineering Competition (MADMEC). They plan to use the money to continue development of the device. This will include using more advanced algorithms to improve the automation of the thermal pulses.

Source: MIT News, Wristify

19 comments
iperov
How skin to breathe? If you frozen just wear warm cloth LOL.
mihafeus
It's just a peltier, heatsink and watch strap. Why did they need 15 iterations of that? It could also be made 50-75% smaller and still have the same effect. And be placed at a more strategic position, with more blood flow. Btw. I don't see a temperature sensor on any of the images. Hardware-wise this seems like a hobbyist afternoon project, it's only the fine tuning that might take some more time.
Mark McGraw
this would be awesome for endurance athletes! Its a billion dollar market. Racing in heat is always an issue for most and if they could keep their temperature down, it would be a HUGE advantage in terms of caloric savings! I hope this market gets explored.
cptn
It's a neat idea -- just from personal experience, running cold water over your wrist on a hot day makes you feel substantially cooler. But it appears that this is simply tricking the mind into making you feel cooler, rather than actually lowering body temperature...? I can see this could be a little dangerous. And considering the public resistance to just wearing warmer clothes, even with rapidly increasing energy costs, I struggle to see people rushing to strap heatsinks to themselves. That said, I'd probably still buy one, if just out of curiosity.
Larry English
heavy sharp dangerous ugly would not cool or heat you anyway during exercise i;d pay about $5 for it how much is it, about $1000? my wife won;t even put on a sweater she would be have to have a complete personality change to put this thing on.. wle
B Peter Brandt-Sorheim
All the same, I want one!
Gregg Eshelman
Want to be cool and look weird at the same time? Take a couple of old CPU heatsinks with fans and fashion something to hold them to either side of your neck, over the carotid arteries and jugular veins. Connect a 9V battery to the fans and you'll feel like you've strapped a couple small blocks of ice to your neck.
Gadgeteer
I already have an item that can make me feel warmer without increasing energy consumption. It's called a sweater. As for cooling, the Sharper Image and other gadget stores have sold powered evaporative personal cooling collars for many years. Much less likely to be damaged than a wrist-mounted device. Or make an unpowered version using sodium polyacrylate or something similar as a gel inside a fabric cover.
Sara Mccracken
I would love this and all menopausal women will thank you!
Sam Joy
I worked with peltier thermoelectrics for about ten years, and one thing which is still true to this day is inefficient of energy these devices are!...The technology has along way to go before they can be used effectively and cost$ to purpose of it's use in any manner worthy of.