Washington, Sep 28: Physicians and environmentalists could soon be using a new class of small, robust and high performance electronic devices capable of dissolving completely in water - or body fluids.
Researchers from Illinois, Tufts and Northwestern Universities have demonstrated a new type of biodegradable electronics technology that could introduce new design paradigms for medical implants, environmental monitors and consumer devices.
"We refer to this type of technology as transient electronics," said John A. Rogers, professor of engineering at the University of Illinois, who led the multidisciplinary research team, the journal Science reports.
"From the earliest days of the electronics industry, a key design goal has been to build devices that last forever - with completely stable performance. But if you think about the opposite possibility - devices that are engineered to physically disappear in a controlled and programmed manner - then other, completely different, kinds of application, opportunities open up," said Rogers.
Three application areas appear particularly promising. First are medical implants that perform important diagnostic or therapeutic functions for a useful amount of time and then simply dissolve and resorb in the body, according to an Illinois statement.
Second are environmental monitors, such as wireless sensors that are dispersed after a chemical spill, that degrade over time to eliminate any ecological impact.
Third are consumer electronic systems or sub-components that are compostable, to reduce electronic waste streams generated by devices that are frequently upgraded, such as cellphones or other portable devices.
The team has built transient transistors, diodes, wireless power coils, temperature and strain sensors, photodetectors, solar cells, radio oscillators and antennas, and even simple digital cameras. All of the materials are biocompatible and, because they are extraordinarily thin, they can dissolve in even minute volumes of water.
The researchers encapsulate the devices in silk. The structure of the silk determines its rate of dissolution - from minutes, to days, weeks or, potentially, years.
"The different applications that we are considering require different operating time frames," Rogers said. "A medical implant that is designed to deal with potential infections from surgical site incisions is only needed for a couple of weeks.
"But for a consumer electronic device, you'd want it to stick around at least for a year or two. The ability to use materials science to engineer those time frames becomes a critical aspect in design," said Rogers.
