This Battery-Free Pacemaker Runs On The Heart’s Own Beat

A Pacemaker Powered by Heartbeats Alone Just Passed Its First Big Test

In 2023, more than 1.6 million pacemaker implantation procedures were performed worldwide, using a small implanted device that sends electrical pulses to keep the heart at a safe rhythm. For many patients, that device needs replacing within a decade, not because anything breaks, but because the battery runs out. Now, a research team has built a pacemaker that ditches the battery entirely, drawing power directly from the heart’s own motion, and in a critical test, it used that harvested power to raise a living heart’s rate on command.

Published in Science Advances, the study describes a fully integrated, leadless pacemaker that generates its own electricity using a triboelectric nanogenerator, or TENG, which converts tiny pressing and releasing motions between materials into an electric charge. It works on roughly the same principle as the static electricity from rubbing a balloon against hair, but miniaturized and triggered thousands of times a day with every heartbeat. The device fits inside the same titanium shell used by a commercially available Medtronic Micra pacemaker, meaning it could theoretically be implanted the same way doctors do it today.

Current leadless pacemakers such as the Micra carry batteries that account for roughly half the total volume and nearly 60% of the weight of the device. When that battery dies, often within five to ten years, a patient must undergo another procedure to replace it or add a new device, meaning younger patients can face multiple surgeries over a lifetime. A self-powered pacemaker that could greatly reduce or potentially eliminate future battery-replacement surgeries could change that equation.

Two Tiny Generators Do the Work of a Battery

At the core of the technology are two compact energy-harvesting units stacked inside the device’s titanium casing, built from layered flexible plates that generate an electric charge when pressed together and pulled apart. When the heart contracts and relaxes, the internal components bounce back and forth like a tiny spring-loaded system, and each heartbeat triggers a cascade of contact-and-separation events. The resulting charge is stored in a small capacitor until enough energy has built up to deliver a pacing pulse.

In lab testing, the device produced a power output per unit volume more than double that of previously reported implanted energy-harvesting devices. Tested across a wide range of simulated cardiac motion strengths, including reduced motion meant to mimic weaker contraction, it kept generating usable electricity, staying within the range needed to power a modern pacemaker’s electronics. An accelerated fatigue test, equivalent to ten years at 60 heartbeats per minute, showed stable output throughout.

The Device Stayed Put in a Pig’s Heart for Four Weeks

Twelve adult pigs were used across the study: eleven for short-term implantation experiments, and one for a full four-week implantation and monitoring period. Using a standard clinical catheter, the device was threaded through a vein in the groin, traveled roughly 60 to 70 centimeters through the body, and was anchored to the inner wall of the right side of the heart, the same procedure used with commercial leadless pacemakers today.

Over four weeks, X-ray images confirmed the device did not shift or detach, and ultrasound showed no disruption to heart valve function. Blood work across five time points showed immune cell counts, platelet levels, and kidney and liver markers all within normal ranges. At the end of 29 days, the animal had gained weight, maintained normal activity, and showed no signs of distress.

When the device was removed, tissue analysis at the attachment site revealed localized scarring consistent with what is typically seen after implantation of commercial leadless pacemakers, including Micra. Tissue farther from the implant site appeared normal.

Harvested Energy Alone Raised a Pig’s Heart Rate

Perhaps the most telling result came from the pacing demonstration itself. Using energy collected by the device, the researchers powered a commercial pacemaker electronic module, a Medtronic Sensia unit. With no battery and no external power source, the device increased a pig’s heart rate from 92 to 100 beats per minute, and in a separate test, from 75 to 120 beats per minute, with stable electrical patterns confirmed by an electrocardiogram.

When the power source was switched mid-experiment from a conventional battery to the TENG-powered device, there was no interruption in pacing signals, showing the harvested energy could take over the power supply without disrupting pacing in that test.

A Long Road Still Ahead

Momentum is real, but so are the caveats. Only one animal completed the full four-week evaluation, and the researchers acknowledge that larger cohorts and longer implantation periods will be needed to understand how tissue scarring might affect energy generation over time. All animal testing used healthy pigs, not the weakened or slow-beating hearts pacemakers are actually prescribed for, and testing in diseased heart models is a critical next step. The pacing demonstration also relied on an older commercial electronic module rather than current-generation Micra electronics, due to access limitations, so future work will need to confirm performance with modern components in a clinically representative setting.

Even so, the core result stands: a pacemaker the size and shape of a commercial device, delivered the way commercial devices are delivered, ran on nothing but a heartbeat and controlled that heart’s own rhythm from inside it. For the millions living with battery-dependent implants today, that proof of concept matters.

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Disclaimer: This article is based on findings from a study involving animal testing and is intended for general informational purposes. It does not constitute medical advice. This technology has not been tested in humans and is not an approved medical treatment.

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