New hydrogel cools and recovers heat from electronic devices

Specific components of electronic devices, such as computer microprocessors, LEDs, and batteries, generate heat when in an operational state. This phenomenon decreases their lifespan, efficiency, and speed. Under severe conditions, this may also lead to fires or an explosion.

ACS’s Nano Letters report that a team of researchers has developed a thermogalvanic hydrogel that solves this problem. The new hydrogel cools down electronics and converts their waste heat into electricity.

The researchers wanted to develop a smart thermogalvanic hydrogel that lowered the device temperature while converting the waste heat into electricity. This new hydrogel constitutes of a polyacrylamide framework infused with specific ions and water.

When heated, two of its ions, ferricyanide and ferrocyanide, transfer electrons between electrodes to produce electricity. Meanwhile, the water present in the gel evaporates to bring down the device’s temperature. Once used, the hydrogel restores itself by absorbing water from its surroundings.

The team demonstrated this new material by attaching it with a cell phone battery that was discharging quickly. The gel brought down the temperature of the battery by 68 F and used the waste energy to produce 5 μW electricity.

The cooling down of the battery ensured its safe operation while the electricity harvested from the waste energy proved sufficient for either controlling the cooling system or monitoring the battery.