Pacemakers, defibrillators and other live-saving implantable devices are powered by batteries that need to be replaced every five to 10 years, requiring costly and risky surgery. The team at the Thayer School of Engineering at Dartmouth College used a flexible polymer piezoelectric film made from layers of poly(vinylidene fluoride) (PVDF) combined with porous structures such as an array of small buckle beams or a flexible cantilever to convert even small mechanical motion to electricity. An added benefit is that the modules can also be used as sensors to enable data collection for real-time monitoring of patients.
"We're trying to solve the ultimate problem for any implantable biomedical device," says John Zhang, professor of engineerat at Dartmouth. "How do you create an effective energy source so the device will do its job during the entire life span of the patient, without the need for surgery to replace the battery?"
"Of equal importance is that the device not interfere with the body's function," added Dartmouth research associate Lin Dong. "We knew it had to be biocompatible, lightweight, flexible, and low profile, so it not only fits into the current pacemaker structure but is also scalable for future multi-functionality."
The device developed over the last three years is the size of a US dime and can be used to charge an implanted battery say the researchers. The two remaining years of funding plus time to finish the pre-clinical process and obtain regulatory approval puts a self-charging pacemaker approximately five years out from commercialization, says Zhang.
"We've completed the first round of animal studies with great results which will be published soon," he added. "There is already a lot of expressed interest from the major medical technology companies, and Andrew Closson, one of the study's authors working with Lin Dong and an engineering PhD Innovation Program student at Dartmouth, is learning the business and technology transfer skills to be a cohort in moving forward with the entrepreneurial phase of this effort."