When it comes to any kind of electronic device, we tend to gravitate toward the ones that are more durable and longer-lasting. While there are certainly benefits to devices that can essentially last indefinitely, things can get a little more complicated when they are implanted in the body. Currently, long-term implantable electronic devices are not widely used because the uncertainty about long-term biocompatibility. Moreover, once a device does its job or surpassed its lifespan, it likely has to be removed, which will typically mean a surgical procedure.
Instead of making an implantable medical device longer-lasting, John Rogers, the University of Illinois Urbana-Champaign professor who also developed electronic skin “tattoos”, flexible electronic implants, and electronic sutures, along with a team of researchers from Tufts University and Northwestern University have taken the opposite approach – developing an implant that literally disappear into nothing after a period of time. Dubbed “transient electronics”, these fleeting devices are meant to be implanted into the body, do their work for days, weeks, or even months, and then safely dissolve and resorb in the body. The benefit would be that these devices would never have to be surgically removed and would disappear after a programmed amount of time, which would no longer make long-term biocompatibility an issue. Moreover, it’s a win for those concerned with the environmental impact of used devices, as transient electronics will leave no trace.
The secret behind these biodegradable devices are circuits made of silicon, magnesium, and other biocompatible metals which are layered thinly enough to dissolve within a matter of days or weeks. The circuits are encapsulated by silk, whose thickness ultimately determines how long the entire implant will take to dissolve. So far, researchers have successfully built several dissolvable devices, including diodes, wireless power coils, temperature and strain sensors, photodetectors, solar cells, radio oscillators, antennas, and even a 64-pixel digital camera. One notable transient device that has already been tested in rats is one that’s designed to monitor and prevent post-surgical infection.
If successful, transient electronics may also someday be found in environmental and chemical sensors. They could also find themselves as the basis for a new, ultra environmentally friendly cellular phone!
University of Illinois: Environmentally safe electronics that also vanish in the body
Tufts University: Smooth as Silk “Transient Electronics” Dissolve in Body or Environment
Northwestern University: Disappearing Act
Journal abstract in Science: A Physically Transient Form of Silicon Electronics