28 September 2012
Researchers develop biocompatible, dissolvable electronics
Researchers have created tiny, biocompatible electronic devices – dubbed transient electronics – that dissolve harmlessly into their surroundings after functioning for a precise amount of time.
The team at the University of Illinois, Tufts University and Northwestern University says the silk-silicon technology could enable medical implants that never need surgical removal, as well as environmental monitors and consumer electronics that can become compost rather than rubbish.
"These devices are the polar opposite of conventional electronics whose integrated circuits are designed for long term physical and electronic stability," said Fiorenzo Omenetto, professor of biomedical engineering at the Tufts school of engineering. "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, depending on the application."
"Imagine the environmental benefits if cell phones, for example, could just dissolve instead of languishing in landfills for years," he added.
The devices use silicon and magnesium in an ultra thin form that is then encapsulated in bio friendly silk protein. As they are only a few nanometres thick, the tiny circuits – from the transistors to the material connecting them – readily dissolve in water or body fluid and are harmlessly assimilated. The properties of the silk can be adjusted to determine the rate of dissolution.
So far, the team has built transient transistors, diodes, wireless power coils, temperature and strain sensors, photodetectors, solar cells, radio oscillators and antennas and even a 64pixel digital camera.
In the future, the researchers envision more complex devices that could be adjustable in real time or responsive to other changes in their environment, such as chemistry, light or pressure.