A team of US researchers has created a new thermoelectric wristwatch that could herald a breakthrough in energy conservation.
The prototype device, titled Wristify, was designed to improve the thermal comfort of a person, which could lead to a reduction in the amount of heating and cooling needed, thereby boosting energy savings.
The watch is effectively a copper “heat sink” which uses a method known as the Peltier effect, which sees low voltage applied to trigger a change in temperature. It monitors the body’s skin and air temperature and sends “tailored stimuli” of hot or cold waveforms to regulate the body’s temperature and allow people to stay comfortable.
“The stimuli are optimised for thermal sensation, providing a comfortable and enjoyable user experience, while maintaining necessary energy efficiency and energy dissipation,” states Wristify’s official website.
Wristify was developed by four engineering students from the Massachusetts Institute of Technology (MIT). The team, consisting of Mike Gibson, Sam Shames, David Cohen-Tanugi and Matt Smith, recently won first prize in MIT’s annual MADMEC competition, which was themed Materials Science Solutions For Sustainability.
“We’re not trying to heat or cool the whole body but rather just heat or cool a part of your body to change the perception of your thermal comfort,” said Gibson, who noted the concept is similar to that of someone placing a cool towel on their head after a workout in order to cool down.
The team is still working to find the optimal cooling and heating cycle for the Wristify prototype, as the researchers found it takes a temperature change greater than 0.1 degrees Celsius per second to make the entire body feel several degrees warmer or cooler.
Currently, Wristify has demonstrated a rate change of 0.4 degrees Celsius per second and can operate up to eight hours powered by a small lithium battery.
“We wanted it to be something you can put on in the morning, run it all day and then plug it in when you get home from work,” said Gibson. “So that’s what we achieved.”
The designers said Wristify is “a dozen times more effective than air conditioning” when it comes to cooling people down.
The investors have also estimated that if the device stops one building from adjusting its temperature by just one degree Celsius, it would save roughly 100 kilowatt-hours of electricity per month.
“Buildings right now use an incredible amount of energy just in space heating and cooling,” said Shames. “In fact, all together this makes up to 16.5 per cent of all U.S. primary energy consumption. We wanted to reduce that number while maintaining individual thermal comfort.”
In Australia, the power used in buildings accounts for approximately 20 per cent of all energy-related greenhouse gas emissions according to the Australian Building Codes Board.
Wristify technology also provides a solution to the problem of thermal regulation, particularly in shared environments such as the office or home, where people with varying optimal temperatures make it difficult to find a happy medium temperature-wise.
The inventors are now exploring the opportunity to bring Wristify to market using their $10,000 first prize from MADMEC.