Researchers reporting in American Chemical Society’s (ACS) Nano Letters have developed a hydrogel that can both cool down electronics, such as cell phone batteries, and convert their waste heat into electricity. Sometimes using electronic devices for too long with too much power can cause them to overheat, which might slow them down, damage their components or even make them explode or catch fire.

A new hydrogel can cool off electronics and generate electricity from their waste heat. Scale bar, 2 cm. Image Credit: ACS Nano Letters. Click image for the largest view.

Some components of electronic devices, including batteries, light-emitting diodes LEDs and computer microprocessors, generate heat during operation. Overheating can reduce the efficiency, reliability and lifespan of devices, in addition to wasting energy.

Xuejiao Hu, Kang Liu, at Wuhan University and Jun Chen at UCLA and colleagues wanted to design a smart thermogalvanic hydrogel that could convert waste heat into electricity, while also lowering the temperature of the device. Until now, scientists have developed devices that can do one or the other, but not both simultaneously.

As explained in the press release at ACS the team 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, water inside the hydrogel evaporated, cooling it. After use, the hydrogel regenerated itself by absorbing water from the surrounding air. To demonstrate the new material, the researchers attached it to a cell phone battery during fast discharging. Some of the waste heat was converted into 5 μW (micro watts) of electricity, and the temperature of the battery decreased by 20° C at the discharging rate of 2.2 C. The reduced working temperature ensures safe operation of the battery, and the electricity harvested is sufficient for monitoring the battery or controlling the cooling system.

This is really a new thing! Its quite an innovative idea implemented successfully with an astonishing result. One can be sure this paper is getting noticed. Moreover, this is an early lab result and there will quite likely be many who seek to improve on this result in hopes of getting to industrial applications or even consumer applications.

Now someone is sure to come up with a closed system on the water side that would make for a very long lasting cooler.


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