University of Illinois researchers have developed heat-triggered self-destructing electronic devices, which they say is a step toward reducing electronic waste and boosting sustainability in device manufacturing. The researchers have also developed a radio-controlled trigger that could remotely activate self-destruction on demand.

The magnesium circuits dissolve when the device is triggered by heat. Image credit: Scott White from University of Illinois The researchers, led by aerospace engineering professor Scott R. White, published their work in the journal Advanced Materials. (Watch a video of the researchers explaining and demonstrating the device.)

The heat-triggered devices use magnesium circuits printed on thin, flexible materials. The researchers trap microscopic droplets of a weak acid in wax and coat the devices with the wax. When the devices are heated, the wax melts, releasing the acid; the acid then dissolves the device.

To remotely trigger the reaction, researchers embedded a radio-frequency receiver and an inductive heating coil in the device. The user can send a signal to cause the coil to heat up, which melts the wax and dissolves the device.

The researchers can control how fast the device degrades by tuning the thickness of the wax, the concentration of the acid and the temperature. They can design a device to self-destruct within 20 seconds to a couple of minutes after heat is applied.

The devices can also degrade in steps by encasing different parts in waxes with different melting temperatures. This gives more precise control over which parts of a device are operative, creating possibilities for devices that can sense something in the environment and respond to it.