There are few things that I hate more than putting on my Bose Ultra Wireless Open Earbuds and having the little critters whisper: “Battery low.” Which is why I’m excited about new research from the Future Interfaces Group at Carnegie Mellon University that’s exploring technology that could power your earbuds, or any other small gadget, by sucking electricity through your skin. In other words, no running out of juice ever again. Just put your buds on and play till your ears fall off.

They call it Power-over-Skin technology. Chris Harrison, an Associate Professor at CMU’s Human-Computer Interaction Institute and co-author of the research, tells me via email that it could become a game-changer for the consumer electronics industry.

The new technology works by transforming the human body into a power delivery medium, using RF (radio frequency) signals to wirelessly transmit electricity across the skin. In simple terms, the system consists of a transmitter and a receiver. The transmitter is a battery-powered unit that couples RF energy to the user’s skin. It could be integrated into existing items like a phone, smartwatch, or a power bank, which could be placed anywhere on the body. The receiver absorbs this RF energy, transforming it into usable power to operate a wearable gadget—like earbuds, rings, or any kind of low-power electronic device—which could be positioned elsewhere on the body.

The researchers demonstrated that this system can transmit energy across significant body distances, all the way from head to toe, with enough power to feed microcontrollers, sensors, and Bluetooth communications. Harrison tells me that the main innovation here is using the human body itself as a capacitive medium for power transfer, bypassing the inefficiencies of traditional airborne RF energy harvesting. The latter wastes most of the transmitted power. “We designed Power-over-Skin with limitations in mind, optimizing power transfer across-body and enabling previously infeasible worn locations,” Harrison says. By leveraging the skin’s properties at specific frequencies, the team achieved practical energy transfer without interfering with human safety standards.

The transmitter outputs a 40 MHz RF signal that is particularly efficient for intra-body power transfer. Harrison explains that the frequencies that allow the best power transfer are the ones where the signal travels most efficiently with the least amount of energy lost, and for this Power-over-Skin technology, that happens at around 40 MHz. “We picked 40 MHz because lower frequencies are easier to produce and lose less energy when passing through the body,” he says.

Interference from environmental RF noise or conductive surfaces are not an issue, Harrison says “Interestingly, if there are other RF noise sources in the environment, our harvesting circuit will attempt to scavenge energy from that too, assuming the frequencies couple to the human body.” The team also designed the transmitter’s frequency to minimize loss when the user makes contact with conductive surfaces. “There is some loss of efficiency if the user touches a conductive surface,” Harrison says, “but we purposely selected frequencies that the body conducts well, so we get good radiation regardless of user grounding.”

According to Harrison, the system’s RF emissions comply with established safety guidelines, meaning it’s safe for humans to use. The concept of using RF energy is not new—similar wireless power transfer methods are used in devices like contactless phone chargers and some medical implants. For example, pacemakers and cochlear implants use wireless energy transfer to recharge or power themselves without direct wiring. However, what makes this system unique is that it uses the human body itself to transmit power over larger distances, which is quite different from typical wireless charging methods that require close contact. The new Power-over-Skin transmitters are deliberately limited to 0.5 watts, which is significantly below the recognized safety threshold of 5 watts for RF exposure. “There is no evidence of ill effects using the RF frequencies we employ,” Harrison says.

A completely different user experience

The technology works through clothing too, thanks to a phenomenon called capacitive coupling. This allows transferring energy through an electric field without direct-to-skin physical contact between the transmitter and the body. This means that you can put your Power-over-skin-enabled phone in your jeans pocket and forget about ever charging your future earbuds or smartwatch. This could radically change the current wearable user experience, which is always interrupted by charging cycles. “If the transmitter is nearer to the torso, like a phone in the pocket, that will yield better performance across the body,” Harrison says, explaining that water is what what helps RF signals travel efficiently through the body. He also says that the body type doesn’t affect efficiency since human tissue is largely consistent in its water content.

This body-powered system could indeed be revolutionary and even make wearables not only more convenient but also more lightweight. Batteries are the heaviest component in most compact devices, taking up space and limiting design options. Removing the need for a battery could fundamentally change their design and usability. The same may happen with implantable medical devices. Powered by body-conducted energy, these could open up significant possibilities for long-term, maintenance-free health monitoring, which Harrison says will be researching over the next year.

Your always-on, no-charge-cycle Apple AirPods and Watches will not happen tomorrow, though. As Harrison points out, “for very low power cycle devices, like glucose monitors that only need to take a reading every few minutes or less, Power-over-Skin could already be a game changer.” But for consumer electronics, the technology needs more development. “The technology is in the research prototype phase, and future work will have to be done to miniaturize and commercialize it, but the biggest question—can it be done at all?—is now answered. That’s a huge step towards consumer feasibility.”