Medical devices that dissolve in water nearer to tests on humans
URBANA — Safe, implantable medical devices that will dissolve rather than be cut out could begin human trials in as little as two years, a University of Illinois professor said Thursday.
The materials could also create compostable electronics such as cellphones, and noncontaminating sensors for water systems.
John A. Rogers, the Lee J. Flory-Founder professor of engineering, led a team of researchers from the UI, Northwestern and Tufts University in developing such "transient" electronics that dissolve in water, the main component of body tissues.
"We have already started animal testing," he said.
Though it sounds like science fiction, it's the bread and butter of Rogers, who has done extensive work in ultra-thin, wearable electronics with medical applications, including a device that wraps onto the brain and electronically helps with seizures.
Such a device could also control artificial limbs.
The work builds on his research with ultra-thin materials. His oft-cited example is that you can't bend a wooden two-by-four, but sliced thin enough, wood becomes very pliable.
In this case, the material includes silicon with magnesium components on a substrate, or flexible base, of silk. The silk structure can be designed to last such time as needed.
People don't think of silicon as something that dissolves, Rogers said.
That's part of the reason engineers have employed it as a useful, permanent substance in electronics.
But again, qualities can change depending on thinness.
"A silicon chip could take 10,000 years to dissolve, but an ultra-thin piece could dissolve in weeks," he said.
In heart surgery, for instance, a monitor could be placed near the organ before the patient is sewn up, Rogers said.
When it has served its useful life, the device would dissolve, and no reopening of the body cavity would be required, Rogers said.
"That could be a matter of a couple weeks, once the patient has been helped," he said.
Reducing surgery also reduces the need for a potentially life-endangering general anesthesia.
Now, Rogers said, a part of the process will be to bring in experts in many disciplines to use their imaginations to conceive new applications.
"We have a baseline of materials that make sense," Rogers said. "We can make high-performance computer systems and sensors. We have successful initial evaluations in animals (mice). But the approval process is time-consuming."
The devices could also heat up to kill germs.
He envisions such medical devices becoming a force in helping aging populations in the U.S. and Japan.
And Rogers said similar devices could serve as wireless sensors to monitor chemical spills without adding even more contaminants to the process.
Also, discarded electronics are a large part of the nation's waste problem.
They could become compostable in the near future, although they would be designed to last longer than the medical devices.
The interdisciplinary team has already invented transient transistors, wireless power coils, temperature and strain sensors, solar cells, and antennas, and even a 64-pixel digital camera, according to an article in the journal Science.
The research was supported by the Defense Advanced Research Projects Agency. The Tufts University team was led by Fiorenzo Omenetto; the Northwestern University team was led by Youggang Huang, a UI press release noted.
Rogers is affiliated with the departments of materials science and engineering, of chemistry, of mechanical science and engineering, of bioengineering and of electrical and computer engineering, and with the Beckman Institute for Advanced Science and Technology and the Frederick Seitz Materials Research Laboratory.