According to the study, published in Nano Letters, some components of electronic devices, such as batteries, light-emitting diodes (known as LEDs), and computer microprocessors, generate heat during operation.
Overheating can reduce the efficiency, reliability, and life of devices, in addition to wasting energy.
Researchers at Wuhan University in China wanted to design a smart thermo-galvanic hydrogel that could convert waste heat to electricity, while lowering the temperature of the device.
So far, scientists have developed devices that can do one or the other, but not both at the same time.
Based on the findings, the research made a hydrogel consisting of a polyacrylamide framework infused with water and specific ions.
When they heated the hydrogel, two of the ions (ferricyanide and ferrocyanide) transferred electrons between electrodes, generating electricity. Meanwhile, the water inside the hydrogel evaporated, cooling it down.
After use, the hydrogel was regenerated by absorbing water from the surrounding air. To demonstrate the new material, the researchers hooked it up to a cell phone battery during rapid discharge.
Some of the waste heat was converted to five microwatts of electricity, and the battery temperature dropped by 68 Fahrenheit.
The reduced working temperature ensures safe battery operation, and the harvested electricity is enough to monitor the battery or control the cooling system, the researchers noted.
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