Researchers in South Korea tested a wireless power system for implanted cardiac pacing in rabbits and pigs. They also measured whether its link could keep delivering power as the receiver stretched or the coils moved out of alignment. Published Sept. 25 in Nature Electronics, the work targets a weakness in conventional inductive links: changes in coil spacing or shape can reduce power delivery.
Seonghyeon Nam, Dae-Hyeong Kim and colleagues combined a nonlinear parity-time-symmetric circuit with a stretchable receiver. A self-oscillating transmitter shifts frequency as magnetic coupling between its coil and the implant changes. The receiver uses liquid-metal traces in an elastomer, which can stretch while continuing to carry current.
The paper’s abstract reports more than 50% power-transfer efficiency under 30% strain and 30-millimetre misalignment. Its supplementary comparison separately lists coil-to-coil efficiency of 50.5% at a 3-centimetre transfer distance with 30% strain, compared with 67.4% at the same distance without strain. The 3-centimetre separation and 30-millimetre misalignment describe different conditions; the figures should not be read as one measurement.
The authors report wireless cardiac pacing and tachyarrhythmia termination in animal models under dynamic in-vivo conditions. A supplementary figure documents a transmitter worn by a freely moving pig and receiver-activation tests with axial separation up to 40 millimetres and lateral displacement up to 30 millimetres. In the in-vivo setup, a 0.4-watt transmitter input supplied 24 milliwatts of regulated output to the stimulation and control electronics. That whole-system result is distinct from the coil-to-coil efficiency above.
Size remains the main engineering constraint. The receiver coil measured 6 by 6 centimetres, and the researchers identify miniaturization as a central challenge because smaller coils transfer power less efficiently. These are animal demonstrations, not clinical validation of a human implant.
Sources
- Original research paper in Nature Electronics (published Sept. 25, 2026).
- Author-provided supplementary information, including efficiency comparisons, receiver dimensions and animal-model results.
- Illustrative image, not the device tested: “X-ray of pacemaker with right atrial and ventricular lead,” by Stephanie C. Torres-Ayala, Guido Santacana-Laffitte and José Maldonado, Wikimedia Commons, CC BY 4.0; displayed at its original aspect ratio.
