Researchers Make a Circuit So Flexible, It Can Wrap Around a Vein

If we really want to get the dream of implantable electronics off the ground, we'll need to figure out how to make circuit boards flexible enough to morph and move with our bodies. Thankfully, a team at The University of Texas at Dallas seems to have solved that, with thin film transistors that are flexible enough to wrap around a nerve or blood vessel.

The team laminated shape-memory polymers on top of thin film transistor circuits to create a chip that's rigid at room temperature, but becomes pliant and flexible at body temperatures. In testing, the film transistors could wrap around a diameter as small as 2.25 millimeters, and when implanted in rats the devices maintained conductivity while flexing with the surrounding tissue.

"Scientists and physicians have been trying to put electronics in the body for a while now, but one of the problems is that the stiffness of common electronics is not compatible with biological tissue," said graduate student Jonathan Reeder, the primary author on the research paper describing the findings. "You need the device to be stiff at room temperature so the surgeon can implant the device, but soft and flexible enough to wrap around 3-D objects so the body can behave exactly as it would without the device. By putting electronics on shape-changing and softening polymers, we can do just that."

If these materials prove reliable, and can be made to encompass more sensory capabilities while wrapping around even smaller structures, they could open up a whole new paradigm of in-body sensors to monitor health conditions like blood pressure heart rate, progression of diseases, or more.

Forget about your fitness-tracking wearable—someday, the sensors could be inside you. [University of Texas at Dallas]