Researchers create heat-triggered, self-destructing electronic devices to help reduce e-waste

Led by aerospace engineering professor Scott R. White, researchers at the University of Illinois have developed heat-triggered self-destructing devices, meant as a new approach to reducing electronic waste, and boosting sustainability in device manufacturing.

In announcing their new technology, the group also detailed a radio-controlled trigger that could remotely active self-destruction on demand.

“We have demonstrated electronics that are there when you need them and gone when you don't need them anymore,” White said. “This is a way of creating sustainability in the materials that are used in modern-day electronics. This was our first attempt to use an environmental stimulus to trigger destruction.”

White’s group worked with John A. Rogers, a Swanlund chair in materials science and engineering and director of the Frederick Seitz Materials Laboratory at Illinois, whose group pioneered transient devices that dissolve in water. The two teams worked on using other triggers to break down devices, including ultraviolet light, heat, and mechanical stress. Their goal was to find a way to disintegrate the device so that manufacturers can recycle costly materials from used or obsolete devices, or so that the devices could more easily break down while sitting in a landfill.

Their heat-triggered approach uses magnesium circuits printed on thin, flexible materials. The team trapped microscopic droplets of a weak acid in wax, and coated the device with said wax. When the devices are heated, the wax melts, releasing the acid upon the circuitry, whereupon the device dissolves quickly and completely. 

To remotely trigger the reaction, the researchers embedded a radio-frequency receiver and an inductive heating coil in the device. When the user is so inclined, he / she can send a signal to the device that will heat the coil up, melt the wax, and dissolve the device. 

“This work demonstrates the extent to which clever chemistries can qualitatively expand the breadth of mechanisms in transience, and therefore the range of potential applications,” Rogers said.

Some things worth noting: the researchers are able to control how fast the device degrades by tuning the thickness of the wax, the concentration of the acid, and the temperature. To date, they’ve demonstrated the ability to dissolve a device as quickly as 20 seconds, or over a period of a couple of minutes. Also, the device can degrade in steps by encasing different parts in waxes with different melting temperatures. Doing this allows greater control over which parts of a device remain operative, and which get destroyed sooner. The point in doing this is to allow for the possibility of more sophisticated devices that can sense something in the environment and respond to it appropriately. 

“We took our ideas in terms of materials regeneration and flipped it 180 degrees,” White said. “If you can't keep using something, whether it's obsolete or just doesn't work anymore, we'd like to be able to bring it back to the building blocks of the material so you can recycle them when you're done, or if you can't recycle it, have it dissolve away and not sit around in landfills.”

Check out a video of the researchers demonstrating and explaining these self-destructing devices below:

The team’s paper, entitled, “Thermally triggered degredation of transient electronic devices,” is available online. 

Via the University of Illinois