For a doctor working with head trauma, monitoring the pressure caused by a swelling brain makes the difference between permanent brain damage or a successful recovery. But sensors are intrusive, and have to be removed. That’s why this new dissolving brain sensor is such a big deal. It’s tiny enough to leave inside the head, giving accurate readings for a few days, before dissolving and being absorbed by the body.
Professor John Rogers is like the MacGyver of medical tech. The Atlantic lists several of his clever hacks—"electric socks for the heart, temporary tattoos that double as medical sensors, and curved cameras based on the eye"—all of which use simple tech in clever ways. Rogers’s new pressure sensor is no different.
Essentially, the sensor is nothing fancier than a regular silicone chip, only much thinner. So thin, in fact, that it will dissolve inside the body in a few days. The actual time it can last inside the body is determined by a polymer capsule that covers it. Once that goes, the silicone quickly breaks down. The chip uses minerals that we normally get through our diets—magnesium, for example—so they just mix with the normal makeup of our bodies.
The tiny sensor, no bigger than the tip of a hypodermic needle, sits inside the head, and flexes when pressure is applied. In rats, the sensor proved as accurate as existing commercial sensors. The sensors don’t work alone: They need a companion device, also tiny, to be implanted nearby, although away from the sensitive brain. This provides power, and lets the sensor talk to the outside world via near-field communication. Right now, this auxiliary chip is only 85% degradable, says the report, but Rogers thinks his team can get it to 100%, matching the sensor.
And he believes his design can be repurposed for other uses too, for use in the stomach, extremities, and the "deep brain."
Rogers is also working on sensors which last for several weeks before they dissolve. He foresees a time when patients can be loaded up with tiny disposable sensors that can keep monitoring them after they return home, making both primary and follow-up care more accurate and more effective. The possibility of skipping your magnesium supplements can be viewed as a happy bonus.