If you insert a conventional silicon chip into the human body, a thousand years will pass before it disappears–the body takes a long, long time to break down silicon and absorb it naturally. If you sliced it thin enough, however, it could dissolve within days, hours or even minutes. You would also have just invented something called transient electronics.
That invention has arrived. Twenty-two researchers from around the world have developed silicon-based transient electronics that can do everything from detect chemicals to kill bacteria using an array of tiny, dissolvable sensors, actuators, power supply systems, and wireless controls. The applications could radically change how we think about deploying sensors and computers in our environment and in our bodies.
The disappearing electronics are composed of nano-thin silicon transistors wrapped in a membrane that dissolves through hydrolysis (when they get wet) as the body or environment breaks down the materials after a specified amount of time. Three applications were immediately apparent, says John Rogers of University of Illinois at Urbana–Champaign, of of the co-authors in an interview with Science (PDF): medical electronics to combat infections and speed healing, environmental sensors that biodegrade, and commercial electronics which dissolve after use instead of sitting in landfills.
“This is a first paper for us on transient silicon electronics, so in that sense, I think it’s a starting point, certainly not an ending point,” says Rogers. “We have a lot of work to do.”
The first implants are still a ways off, but the team (which received support form the US military’s research and development agency DARPA is looking at ways to start inserting thin films with implantable surgical devices such as pace makers, or even using the tech at wound sites to kill bacteria using heat rather than chemical antibiotics.
The biggest challenge to achieve widespread use finding a way to mass produce the devices, rather than handcrafting them in expensive academic clean rooms. The vision, says Rogers, is to eventually make transient silicon electronics the way Intel makes chips: “high-volume, low-cost, very precise control over the device properties.”