In the past, medical implants were a pretty permanent situation; if you had surgery to get something like a pacemaker, you’d have to have surgery to take it out. But in the not-so-distant future, biomedical devices may be able to harmlessly dissolve after a certain amount of time—completely changing how doctors can heal wounds, repair a broken bone, or even treat cancer. A new biodegradable battery could power the device, and then melt away.
Two years ago, materials scientist John Rogers at the University of Illinois at Urbana-Champaign pioneered electronics that could safely degrade inside the body to treat disease. The only problem: They needed a power source. Now, Rogers has unveiled a tiny "bioresorbable" battery that can do the job.
"For biomedicine, we envision that they will be most useful as power supplies for bioresorbable electronics, or 'electroceuticals.' that can monitor and/or perform therapy on a transient process in the body, such as the healing of an internal wound, the mending of a fractured bone, or the treatment of a cancerous tumor," Rogers says.
The batteries could be equally useful outside the body, since they safely biodegrade in the environment as well. In an oil spill, for example, they could be used to power sensors scattered over the water to monitor pollution. After a short period of time, they’d melt. When it dissolves, it releases just nine milligrams of magnesium.
They could also be added to anything that only needs power for a short time. "There are lots of devices these days that are essentially electronic throwaways— trinkets, LEDs, active RFID tags, etc.—that require some amount of power, but are not meant to last forever," Rogers says. "Here, a bio/eco resorbable battery could eliminate otherwise hazardous waste streams that arise from conventional batteries."
It's easy to wonder if this could also spur a new generation of quantified self devices when it hits the market, for those who aren't satisfied with wearable tech alone.
For now, the battery is still in development; it can only last for a day. Rogers and his team are working to make it last for months. "For use with programmable drug release systems, or with devices that can monitor a wound healing process, then timeframes between a couple of weeks to several months might be long enough," he explains. "We think that this timeframe addresses many of the applications that we have in mind."
By the end of the year, the researchers hope to build the batteries into a basic implantable device for non-human testing.