31 January 2012
Elastic electronics pave way for bio-integrated medical devices
A researcher is developing an electronic tattoo that has the potential to prevent epileptic seizures before they happen, or that could be placed on the surface of a beating heart to monitor its functions.
John Rogers, materials scientist at the University of Illinois Urbana Champaign, believes he has bridged the gap from silicon, wafer based electronics to biological, 'tissue like' electronics – effectively blurring the distinction between electronics and the human body.
Rogers' elastic electronics, developed with support from the National Science Foundation, builds upon years of collaboration between Northwestern University engineer, Yonggang Huang. The researchers had previously developed flexible electronics for hemispherical camera sensors and other devices that conform to complex shapes.
According to Rogers, the elastic electronics are made of tiny, wavy silicon structures containing circuits that are thinner than a human hair. As the skin moves and deforms, the circuit can follow the deformations in a non-invasive way, monitoring and delivering electrical impulses into living tissue. Rogers believes the technology will pave the way for a range of 'bio integrated' medical devices.
One example is what Rogers describes as an electronic sock – whereby elastic electronics are wrapped around a rabbit heart like a stocking. "It's designed to accommodate the motion of the heart, but at the same time keep active electronics into contact with the tissue," Rogers said. He has developed a version of the sock that can inject current into the heart tissue to detect and stop certain forms of arrhythmia, as well as catheter prototypes that can be inserted through the arteries into the chambers of the heart to map electrical activity and provide similar types of therapies.
On the basis if this research, Rogers believes that the technology could one day lead to devices such as an implantable circuit that diagnoses and treats seizures by injecting current into the brain. In theory, the device could detect differences in brainwave activity that occur just before a seizure sets in and automatically counteract any electrical abnormalities. Prototypes are now being tested that can detect muscle movement, heart activity and brain waves by simply being placed on the surface of the skin – not unlike a tattoo. According to Rogers, the prototypes can detect the body's electrical activity almost as well as conventional rigid electrode devices.
Rogers believes that the devices' size could also be used to monitor the health of premature babies in a noninvasive way.
Read more on electronic tattoo research.