World's tiniest pacemaker is smaller than grain of rice

This picture obtained on April 2, 2025 shows a pacemaker next to a single grain of rice on a finger. The world's tiniest pacemaker, a temporary heartbeat regulator smaller than a grain of rice that can be injected, controlled by light, and eventually dissolves. [AFP]

Scientists said Wednesday they have developed the world's tiniest pacemaker, a temporary heartbeat regulator smaller than a grain of rice that can be injected and controlled by light before dissolving.

While still years away from being tested in humans, the wireless pacemaker was hailed as a "transformative breakthrough" that could spur advances in other areas of medicine.