Developed by University of Connecticut (UConn) engineers, this flexible and dissolvable device is designed to replace existing implantable pressure sensors that potentially contain toxic components and avoid the need for invasive surgery.
Thanh Duc Nguyen, an assistant professor at UConn Health, said: "We are very excited because this is the first time these biocompatible materials have been used in this way.”
When pressure is applied against the sensor, it emits a small electrical charge known as the piezoelectric effect. These electrical signals can be captured and transmitted to another device for review by a doctor. UConn researchers believe this technique could also provide electrical stimulation for tissue regeneration.
"Medical sensors are often implanted directly into soft tissues and organs. Taking them out can cause additional damage,” Nguyen explained. “We knew that if we could develop a sensor that didn't require surgery to take it out, that would be really significant."
One major challenge UnConn faced was achieving the piezoelectric effect within the biodegradable polymer, Poly(L-lactide). A graduate in Nguyen's lab was responsible for the breakthrough achieved by heating, stretching and cutting the material at just the right angle so that its internal molecular structure was altered and adopted piezoelectric properties.
The UConn sensor is made of two layers of piezoelectric Poly(L-lactide) film, sandwiched between tiny molybdenum electrodes and then encased with layers of polylactic acid.
"There are many applications for this sensor," said Nguyen. "Let's say the sensor is implanted in the brain. We can use biodegradable wires and put the accompanying non-degradable electronics far away from the delicate brain tissue, such as under the skin behind the ear, similar to a cochlear implant. Then it would just require a minor treatment to remove the electronics without worrying about the sensor being in direct contact with soft brain tissue."
Nguyen explained that the ultimate goal is to extend the functional lifetime of the sensor and create completely biodegradable sensor system.
