Mesh Woven Into Heart Tissue Harvests Energy From Motion
The approach could offer a more biocompatible way to power implants
Edd Gent54m
4 min read
Edd Gent is a contributing editor for IEEE Spectrum.
A 3D fluorescence image shows the woven structure of the microscopic energy harvesting mesh.
Siqi Wang
Medical implantslike pacemakers anddeep brain stimulatorsnow rely onbatteriesthat are bulky, stiff, and eventually need replacing. But what if these devices could be powered by the body itself? Researchers at the University of Massachusetts, Amherst have now built an ultra-thin, flexible mesh that can be integrated into living tissue and generate energy from its motion.
Implanting large, rigid components into the body triggers an immediate reaction from the immune system, known as the foreign body response. This causes widespread inflammation followed by the buildup of scar tissue, which ultimately seals the device off from the rest of the body. In an effort to increase the biocompatibility of theirimplants, biomedical engineers are experimenting with soft andflexible electronicsthat don’t elicit such a strong reaction. However, batteries remain a major bottleneck, because efforts to make them smaller and more flexible reduce power capacity.
One promising alternative is to instead harvest energy from the body itself by capturing mechanical energy generated by the contraction of muscles, such as heartbeats, or the movement of fluids. Existing approaches have typically relied on relatively bulkyenergy harvestingdevices sutured onto organs, which have struggled to generate practically useful amounts of power. But a new approach from the UMass Amherst researchers instead relies on a flexible, biocompatible mesh woven into the tissue and studded with tiny piezoelectric devices, which convert mechanical energy into electricity. In researchpublished inScience Advances,the team showed that a mesh grown into cardiac tissue in the lab could achieve energy densities ten times that of previous strategies.
“If we can distribute the energy harvesting units across the tissue down to the size of a single cell...then I think this really can shift the paradigm in terms of more efficient, more biocompatible energy harvesting,” saysJun Yao, an associate professor of electrical andcomputer engineeringat UMass Amherst, who led the research.
Decentralizing implant power sources
The core insight behind the new approach, says Yao, was the fact that biology doesn’t rely on a central power supply like a battery. Instead energy production happens at the cellular level exactly where it’s needed, which is part of the reason why the body is so energy efficient.
Energy harvesting approaches that rely on bulky “centralized” devices are inherently inefficient, says Yao, because much of their footprint is taken up with packaging and other components that aren’t involved in harvesting. So his team set out to create a device more closely aligned with nature’s approach, building onprevious researchinto flexible, biocompatible meshes that can be integrated into tissue to act as sensors.
The team’s mesh consists of a grid of ultrathin ribbons of polymer with a thin conductive wire of platinum running through them. Within the ribbons, the team also embedded 470-micrometers-long strips of a piezoelectric ceramic material, lead zirconate titanate. The result was a 7-by-8-milimeter mesh with 64 energy harvesting units all aligned in the same direction.
Each ribbon in the mesh is roughly 20 μm wide—about the size of cardiac muscle cells—which greatly increases bio-compatibility, says Yao. “If you have a bulky, rigid material getting close to [cells], they feel it and they don’t like it,” he says. “If things are smaller than the cell itself, and the mechanical properties are as soft as a cell, they feel much less stressed.”
So, when the team then seeded the mesh with stem-cell derived human heart cells and left them to develop for 15 days, the cells happily grew around the mesh to create a continuous sheet of cardiac tissue.
When this tissue started to spontaneously contract—a natural, involuntary response of cardiac muscle tissue—the researchers observed corresponding voltage pulses from the mesh. The team calculated that the mesh achieved an energy harvesting density of more than 10 microwatts per cubic centimeter, which is roughly an order of magnitude better than the performance previous centralized designs achieved.
That kind of output makes it realistic to power medical implants in a relatively modest volume, says Yao. But crucially, because the mesh can be seamlessly integrated into tissue, there’s nothing preventing significantly larger meshes being used to generate more power. “Its basically penetrated into the tissue at the single cell level, so you are not confined by these kind of geometric or size parameters,” he says.
Integrating bioelectronic meshes into the body
The new research is “a significant advance in bioelectronic integration” that could support new kinds of distributed bioelectronic devices, saysBozhi Tian, a professor of chemistry at the University of Chicago, who also works on bioelectronic meshes. An important next step though, will be to demonstrate that it works in three-dimensional tissues inside the body without disrupting normal physiological processes.
For practical applications, Tain adds, the hardest problem will be to maintain a safe, stable interface with the tissue over multiple years. “The mesh must survive repeated motion, avoid fibrosis [excess scar tissue], and preserve cardiac mechanics and electrical conduction,” he says. “Reliable implantation, efficient power collection and storage, and adequate output during illness or reduced movement are also essential.” The lead-based ceramic currently used by the team also raises toxicity concerns, so will likely have to be replaced, he adds.
While it remains a distant prospect, Yao already has ideas about how to integrate the mesh into the body. One option would be to grow tissue grafts with the mesh inside and then transplant them, but a more interesting possibility would be to borrow an idea from Elon Musk’sbrain-computer interfacecompanyNeuralink. It hasdeveloped a surgical robotthat threads flexible electrodes into the brain much like a sewing machine, and Yao says this kind of approach could be used to directly implant a “3D forest” of energy harvesting ribbons into tissue.
Yao also thinks that there may be more promising sources of energy to harvest from than mechanical motion, which requires implantation in parts of the body where motion is constant. In the future, he wants to explore devices that can exploit the biochemical energy that the body itself relies on. “That probably is the ultimate version of this system,” he says. “It’s generic, it can be placed anywhere.”
From Your Site Articles
- Implantable Batteries Run on the Body’s Oxygen ›
- Energy Harvesting for Wearable Technology Steps Up ›
Related Articles Around the Web
energy harvestingsoft electronicsdistributed energymedical implantspiezoelectricsEdd GentEdd Gentis a freelance science and technology writer based in Bengaluru, India. His writing focuses on emerging technologies across computing, engineering, energy and bioscience. He's on Twitter at@EddytheGentand email at edd dot gent at outlook dot com. His PGP fingerprint is ABB8 6BB3 3E69 C4A7 EC91 611B 5C12 193D 5DFC C01B. His public key ishere.DM for Signal info.
How Beta Technologies Is Clearing the Runway for Electric Flight
23h
14 min read
Your Robot’s Safety Functions Already Work. What If the Input Lies?
27 Oct 2026
5 min read
I Used AI to Fake a Scientific Paper. Here’s What Happened
27 Oct 2026
13 min read
