Engineers from Northwestern University revealed what they called “the world’s smallest pacemaker” on April 2, with the tiny device measuring smaller than a grain of rice.The university said the pacemaker is so small that it can fit inside the tip of a syringe to be inserted into the body and dissolve after it’s no longer needed.The pacemaker is paired with a small, flexible, wireless device that sits on a patient’s chest to control heart pacing.If the device detects an irregular heartbeat, it automatically shines a light pulse to activate the pacemaker. The short pulses, which penetrate through the patient’s skin, breastbone and muscles, control the heartbeat. The light then flashes on and off at a rate that corresponds to the correct pacing.The university said that although it can work with hearts of all sizes, the pacemaker is particularly well-suited to the tiny, fragile hearts of newborn babies with congenital heart defects.Footage by John A Rogers of Northwestern University shows the size of the pacemaker on a finger and the detector flashing to the pulses of the pacemaker. The university also released a graphic that detailed how the pacemaker works.Northwestern University also released images comparing the size of the pacemaker to a quarter, a penny, a pencil tip, and the eye of a needle. Credit: John A. Rogers/Northwestern University via Storyful