Ultra-thin electronics that melt in the body

Scientists have developed ultra-thin electronics that dissolve inside the body once their job is done, and could be used for a range of medical roles.

Researchers from the Beckman Institute, University of Illinois and Tufts University developed the device from components made of silicon and magnesium oxide, and placed in a protective layer of silk, the BBC News reported.

The vanishing devices are part of a field termed “transient electronics” and researchers described them as the “polar opposite” of traditional electronics, which are built to be stable and to last. Getting the electronics to fade away in a controlled manner relies on two scientific developments - getting the electronics to dissolve at all and using a shell to control when that happens.

Silicon dissolves in water but the problem is that the size of components in conventional electronics means it would take an eternity. The researchers used incredibly thin sheets of silicon, called a nanomembrane, which can dissolve in days or weeks.

The speed of melting is controlled by silk. The material is collected from silkworms, dissolved and then allowed to reform. Altering the way the dissolved silk crystallises changes its final properties - and how long the device will last.

“Transient electronics offer robust performance comparable to current devices but they will fully resorb into their environment at a prescribed time, ranging from minutes to years,” Professor Fiorenzo Omenetto, from Tufts school of engineering, said. A range of uses have already been tested in the laboratory including a 64-pixel digital camera, temperature sensors and solar cells.

John Rogers, a mechanical science and engineering professor at the University of Illinois, told the BBC that one likely use would be in wounds after surgery. “Infection is a leading cause of readmission, a device could be put in to the body at the site of surgery just before it is closed up,” he said.

“But you would only need it for the most critical period around two weeks after surgery,” he added. The team of researchers have tested on rats a device that heats a wound to kill off bugs. There are also ideas around using the technology to slowly release drugs inside the body or to build sensors for the brain and heart.