Researchers at the University of California San Diego have designed a new type of wearable patch that has the potential to provide users with personal heating and cooling capabilities. Scientists believe it has the potential to help users save money on heating and air conditioning in the future.
The patch is stretchy and soft, and is worn against the user’s skin. From there, it adjusts its temperature accordingly to keep the wearer comfortable regardless of ambient temperature changes. The device is powered by a battery that is stretchable and flexible; and has the capacity to be embedded in the clothing of the user.
Currently, the device is at the proof-of-concept stage. It is designed from thermoelectric alloys made of bismuth telluride alloys. This means that the materials incorporated in the device rely on electricity to create a temperature difference. The materials are soldered to thin copper electrode strips and then placed between two sheets of stretchy elastomer, which allows the device to move with the user’s body. The sheets are constructed from a combination of rubber materials known as Ecoflex and aluminum nitride powder, which has a high thermal conductivity. The user can adjust the temperature to suit their specific needs, and the device will heat or cool accordingly.
The patch operates thanks to an electric current, which moves heat from one elastomer sheet to another. The current moves heat along as it travels across the bismuth telluride pillars. This results in one side of the patch heating up, while the other cools down. This allows scientists to move heat either towards the skin to warm the subject, or away from the skin to keep the user cool.
To test the device, the prototype was embedded into a mesh armband. Next, a subject with the armband was placed in a temperature-controlled environment, and within two minutes the patch had cooled to 89.6 degrees Fahrenheit. The prototype was able to maintain that temperature against the subject’s skin even as the ambient temperature was lowered to 71.6 degrees Fahrenheit and raised to 96.8 degrees Fahrenheit.
Although further testing and research are required on this subject, scientists are hopeful that this technology could one day be utilized in wearables to create clothing that can keep users warm or cool. They hope to commercialize their design within the next few years.