Modern gadgets become obsolete in just a few years, but they contain components that should not just be tossed in the trash. In order to reduce the amount of e-waste and make devices easier to recycle, researchers at the University of Illinois have developed electronics that can be prompted to self-destruct on demand.
To do this, magnesium circuits are printed on thin, flexible materials and then coated the device with wax that contains acid. Then, when the device is exposed to heat, the wax melts and releases the acid, which dissolves the electronics. Using this process, the device is degraded so that components can easily be recycled or destroyed. The researchers also embedded a radio frequency receiver and an inductive heating coil, so that a user can remotely send a signal to the device to heat the coil, which melts the wax and releases the acid to destroy the electronic components.
We wondered if coating the devices in the acidic wax would cause any problems for the device’s function or safety, so we reached out to the researchers to learn more. Dr. Scott White said the wax only contains microscopic droplets of a weak acid that “isn’t strong enough to melt your phone, nor harm you in any way.” He also confirmed that the coating has no negative impact on device function, because it only interacts with the device if it is triggered by heating.
According to White, the biggest challenge was “finding the right combination of materials to achieve stable operation under normal conditions and then rapid destruction under the target conditions.” He explained that “these two objectives are somewhat at odds with each other. Things you do to make something stable don’t necessarily help it to become unstable at the target conditions, and vice versa.”
In addition to heat, the researchers have found several other ways to trigger the devices to self-destruct, such as UV light or mechanical stress. Currently, White says his team is “busy exploring new stimuli that can trigger device functionality (beyond just destruction).”