When John Peterson received a temporary pacemaker after cardiac surgery, he faced a difficult choice: wait for it to fall out naturally or undergo a second operation to have it removed. It is a dilemma thousands of patients face every year. But researchers at Northwestern University and Sungkyunkwan University may have found a way to end it entirely.
A team led by Jong Uk Kim and Seung Gi Seo has developed a tiny, implantable device that delivers electrical stimulation to the heart, nerves, or muscles — and then dissolves harmlessly into the body once its work is done. Described in a paper published in Nature Electronics, the system uses a bioresorbable silicon phototransistor just five micrometers thick, thin enough to integrate seamlessly with living tissue. An external near-infrared light source wirelessly powers and controls the device, meaning no batteries, no wires, and no second surgery required.
"Wireless bioresorbable systems for electrical stimulation can deliver electrotherapy over clinically relevant timeframes, and then subsequently dissolve away in a harmless fashion," the researchers wrote.
The technology addresses a significant gap in modern medicine. Existing temporary implants — pacemakers for arrhythmias, neurostimulation devices for epilepsy, or electrodes for nerve injury recovery — often must be surgically removed once treatment concludes. Removal carries risks of infection, tissue damage, and complications, particularly in patients who are already fragile. This new device sidesteps that problem entirely by simply disappearing.
What makes the system especially versatile is its ability to generate multiple types of electrical pulses. Unlike earlier single-pulse devices, Kim and Seo's system can produce monophasic, biphasic, and polyphasic waveforms — meaning it can send current in one direction, reverse it, or modulate both direction and intensity across multiple phases. This flexibility allows clinicians to tailor stimulation to specific conditions, whether that is correcting an irregular heartbeat or coaxing damaged nerves back to function.
Early testing in both small and large animal models produced encouraging results. The device successfully paced animal hearts in single- and dual-chamber configurations and stimulated the phrenic nerve to control diaphragm movement — a critical function for patients with respiratory weakness. The near-infrared system penetrated tissue deep enough to activate the implant reliably, suggesting it could eventually work inside a human chest or abdomen.
The implications stretch beyond cardiology. The same platform could be adapted to manage gastroparesis, a condition where the stomach muscles fail to move food along properly, or to support nerve regeneration after injury. Because the device leaves no trace, patients could receive targeted, powerful electrotherapy without the physical and psychological burden of an permanent foreign object.
Human trials are still ahead, and the researchers acknowledge questions about dissolution timing and long-term safety that need answers. But the foundation they have built suggests a future where a device could heal you and then vanish — no scalpel, no follow-up visit, no reminder of the illness that brought it there in the first place.