Engineers Develop World's Smallest Light-Activated Pacemaker

(Photo by Liangsong Zeng and Lichao Tang, Northwestern University)

Designed for temporary use, especially in pediatric patients, the device naturally dissolves after recovery, eliminating the need for surgical removal. 

"The technology addresses a critical clinical need for temporary pacemakers following pediatric heart surgeries, where extreme miniaturization helps reduce the burden on tiny, fragile hearts," said Ouyang.

When the skin patch detects an irregular heartbeat, it automatically shines a light pulse to activate the pacemaker. These short pulses—which penetrate through the patient's skin, breastbone and muscles—control the pacing.

Many patients require temporary pacemakers after heart surgery—either while waiting for a permanent pacemaker or to help restore a normal heart rate during recovery.

Instead of using near-field communication to supply power, the new, tiny pacemaker operates through the action of a galvanic cell, a type of simple battery that transforms chemical energy into electrical energy. Specifically, the pacemaker uses two different metals as electrodes to deliver electrical pulses to the heart. When in contact with surrounding biofluids, the electrodes form a battery. The resulting chemical reactions cause the electrical current to flow to stimulate the heart.

The study was co-led by researchers at Dartmouth, Northwestern, and the University of Chicago.