Engineers at the University of Massachusetts Amherst have designed an ultrathin, flexible mesh capable of harvesting energy directly from human cells to power implantable electronics without batteries. Published in Science Advances, the breakthrough addresses the critical challenge of removing bulky, finite power sources from medical devices.
Engineering a Tissue-Integrated Power Supply
Traditional implantable electronics—including pacemakers, defibrillators, deep brain stimulators, and cochlear implants—rely on centralized batteries. Traditional energy storage units take up considerable space and inevitably deplete over time, while shrinking their dimensions and increasing their pliability diminishes their energy capacity. Human bodies want to reject systems that come with bulk batteries.
To bypass these architectural limitations, a team led by researchers at the University of Massachusetts Amherst turned to the human body itself. “Our bodies are 24/7 power plants. Every single cell produces its own power,” explains Siqi Wang, a Ph.D. student in the university’s Riccio College of Engineering. This cellular output manifests as electrical signals, such as nerve impulses, alongside mechanical forces like contracting muscle tissue.
The research team built a distributed energy-harvesting architecture to capture this biological output. They started with an array of thin ribbons constructed from lead zirconate titanate, commonly known as PZT. This material converts mechanical energy into electrical energy. The PZT ribbons were then mounted onto an ultrathin, ultraflexible polymer platform.
Seeding Human Cardiac Cells onto PZT Ribbons
To ensure the device worked with the body, the team seeded the PZT-loaded polymer platform with living human cardiac cells. As these cells grew, they meshed into and around the flexible structure. The resulting composite device moves and looks like human tissue while functioning as a battery that never needs to be replaced.
According to Jun Yao, associate professor in UMass Amherst’s Riccio College of Engineering and the paper’s senior author, the platform produced a power density—defined as the energy output per unit volume—that was 10 times higher than that of conventional centralized power systems. Because the underlying films are ultrathin, they can be stacked in layers. This layering drastically increases the amount of power on tap while remaining noninvasive.
“The beauty of this system is how noninvasive and powerful it is. Our bodies want to reject systems that come with bulk batteries, but when the device exists at the cellular level, you get vastly improved biocompatibility,” says Jun Yao.
UMass Amherst Team Establishes Blueprint for Batteryless Medical Implants
While the device successfully demonstrates high-density energy generation, the technology remains only in the lab.
By shifting from a centralized electrical engineering paradigm to a distributed, biology-inspired framework, the UMass Amherst team has established a blueprint for batteryless medical implants. The study, detailed under DOI: 10.1126/sciadv.aei5963, provides a foundation for future advancements in noninvasive biomedical engineering.
