Like many sustainable folks I’m hopeful of clean energy and green electronics in the future. I’ve seen glimmers of embedded tech fabrics with solar cells and tiny batteries and plenty of flexible circuits. However, the thing that really gets my juices going (spoiler alert) is energy harvesting devices. This week I read about a group of researchers at North Carolina State University’s College of Engineering that have created a wearable for just such purposes according to NC State News. Their compact wearable prototypes convert body heat efficiently to energy, which in the past has been a tricky thing.
“Wearable thermoelectric generators (TEGs) generate electricity by making use of the temperature differential between your body and the ambient air,” says Daryoosh Vashaee, an associate professor of electrical and computer engineering at NC State and corresponding author of a paper on the work. “Previous approaches either made use of heat sinks–which are heavy, stiff and bulky–or were able to generate only one micro-watt or less of power per centimeter squared (µW/cm2). Our technology generates up to 20 µW/cm2 and doesn’t use a heat sink, making it lighter and much more comfortable.”
The TEG is sandwiched between two layers of thermally conductive fabric. One layer is next to the body and coated with polymer to spread the heat, yet keep it from dissipating, while the other layer allows unused heat to escape. Although there isn’t much detail given about the construction of the TEG, there is mention that the work is part of the National Science Foundation’s Nanosystems Engineering Research Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST) at NC State.
The team worked with different prototypes for the TEG including an embedded t-shirt, as well as an armband. Their tests indicate the upper arm as the best location for energy harvesting. In fact, future uses may include powering EKG sensors. It’s exciting work for these students and you can imagine how these flexible TEGs become more powerful once they are increased in size for the desired device. Did anyone notice that these guys are using a very nice Fluke Multitester that happens to be in our shop? If you want the whole burrito, this one is the 87V industrial model for serious EEs. It’s auto-ranging, durable, reliable, super fast and even has temperature. So, when you are ready for some serious testing, we’ve got you covered.
Every Wednesday is Wearable Wednesday here at Adafruit! We’re bringing you the blinkiest, most fashionable, innovative, and useful wearables from around the web and in our own original projects featuring our wearable Arduino-compatible platform, FLORA. Be sure to post up your wearables projects in the forums or send us a link and you might be featured here on Wearable Wednesday!