Wearable integrated thermocells based on gel electrolytes use body heat
Electronics integrated into textiles are gaining in popularity: Systems like smartphone displays in a sleeve or sensors to detect physical performance in athletic wear have already been produced. The main problem with these systems tends to be the lack of a comfortable, equally wearable source of power. Chinese scientists are now aiming to obtain the necessary energy from body heat. In the journal Angewandte Chemie, they have introduced a flexible, wearable thermocell based on two different gel electrolytes.
Our muscle activity and metabolism cause our bodies to produce constant heat, some of which is released through the skin into the environment. Because of the relatively small temperature difference between skin (approximately 32°C) and the temperature of our surroundings, it is not so easy to make use of body heat. Previous thermoelectric generators, such as those based on semiconductors, produce too little energy, are costly, or are too brittle for use in wearable systems. Thermocells with electrolyte solutions are difficult to integrate into extensive wearable systems. A team led by Jun Zhou at Huazhong University of Science and Technology (Wuhan, China) has now found a solution to this problem: thermocells with gel-based electrolytes.
The researchers are making use of the thermogalvanic effect: if two electrodes in contact with an electrolyte solution—or an electrolyte gel—are kept at different temperatures, a potential difference is generated. The ions of a redox pair in the electrolyte can rapidly switch between two different charge states, accepting or releasing electrons at electrodes with different temperature. In order to use this to produce a current, the scientists combined two types of cells containing two different redox pairs. Each cell consists of two tiny metal plates that act as electrodes, with an electrolyte gel in between. The first cell type contains the Fe2+/Fe3+ redox pair. The second type of cell contains the complex ions [Fe(CN)6]3?/[Fe(CN)6]4?. Because of the choice of these redox pairs, in cell type 1, the cold end gives a negative potential, while in type 2, the cold end gives a positive potential.
The researchers arranged many of these two types of cells into a checkerboard pattern. The cells were connected to each other by metal plates alternating above and below, to link them into a series. They then integrated this “checkerboard” into a glove. When the glove is worn, the desired temperature difference results between the upper and lower plates. This produces a voltage between neighboring cells, and the voltage adds up. This makes it possible to generate current to power a device or charge a battery.
In an environment at 5 °C, it was possible to produce 0.7 volts and about 0.3 µW. By optimizing this system, it should be possible to improve the power, even with smaller temperature gradients.
Learn more: Body Heat as a Power Source
The Latest on: Thermocells
via Google News
The Latest on: Thermocells
- Wearable power: The heat is on you on September 14, 2016 at 5:00 pm
Wearable integrated thermocells based on gel electrolytes have been developed that are powered by body heat. The concept of wearables is not just a buzz phrase for technophilic lifestyle magazine it i... […]
- Mosquito numbers set to spike in Regina on July 14, 2016 at 5:48 pm
“The newest options is the Thermocells,” Flaman said. “There’s no odour to them, [you] can’t smell them, which is a big thing for the hunters. They just run off a butane cannister and a cartridge that ... […]
- New thermocell technique could harvest power from waste heat at power plants on July 17, 2013 at 7:57 am
More traditional thermocells contain water, which boils off at those temperatures. The Monash researchers used a liquid packed with electrolytes, which give it a higher boiling point than water. Therm... […]
- Matt’s Favorites: Compuware At 10 Downtown, Heat Wave Stretches Infrastructure, Wet Spacesuit And More on July 15, 2013 at 5:00 pm
And how many of these 10 sci-fi stories that predicted the surveillance state have you read? * In energy news, these thermocells make valuable electricity out of what is now ‘waste heat.’ * As it turn... […]
- A strange year already on March 17, 2012 at 11:19 pm
I can only imagine what the near future holds in the pine flats with the heat and early rain we are getting. Thank the Lord for Thermocells! Last year I flew to Wyoming to hunt. We were several hours ... […]
- Making good use of hot air on March 8, 2010 at 4:00 pm
Thermocells based on carbon nanotubes (and, thus, cheaper and more efficient than the kind based on platinum) could help capture the wasted heat put off by everything from car exhaust pipes to power s... […]
- Carbon nanotube thermocells could convert heat waste to energy on March 1, 2010 at 4:00 pm
(Nanowerk News) A study published in the American Chemical Society's journal Nano Letters reveals that thermocells based on carbon nanotube electrodes might eventually be used for generating electrica... […]
- Nanotube Thermocells Hold Promise For Converting Heat Waste To Energy on March 1, 2010 at 4:00 pm
(PhysOrg.com) -- A study published in the American Chemical Society's journal Nano Letters reveals that thermocells based on carbon nanotube electrodes might eventually be used for generating electric... […]
- Nanotube Thermocells Hold Promise as Energy Source on February 25, 2010 at 4:00 pm
A view from an electron microscope shows the multiwalled carbon nanotube "buckypaper" used in the new thermocells. (PhysOrg.com) -- A study published in the American Chemical Society's journal Nano Le... […]
via Bing News