The team, led by Prof Scott White of the University of Illinois’ Beckman Institute for Advanced Science and Technology, also developed a radio-controlled trigger that could remotely activate self-destruction on demand.

“We have demonstrated electronics that are there when you need them and gone when you don’t need them anymore. 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,” said Prof White, who is the senior author on the study published in the journal Advanced Materials.

The heat-triggered devices use magnesium circuits printed on very thin, flexible materials.

The scientists 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 dissolves the device quickly and completely.

To remotely trigger the reaction, they 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.

“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,” said co-author Dr John Rogers.

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 also can 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 sophisticated devices that can sense something in the environment and respond to it.