Researchers at the University of Buffalo are developing technology to make implantable pacemakers battery-free. The advancement is based upon a piezoelectric system that converts vibrational energy - created inside the chest by each heartbeat - into electricity to power the pacemaker. The technology may eliminate the medical risks and costs of having a battery replacement every five to 12 years for millions of people worldwide. M. Amin Karami, PhD, assistant professor of mechanical engineering, is leading the research. Karami initially designed a flat piezoelectric structure for a conventional pacemaker. A prototype generated enough power to keep the pacemaker running at a range of 7 to 700 beats per minute. With the development of wireless pacemakers, however, he has revamped the design to accommodate the smaller, tube-shaped device. He is currently building the new prototype and expects to have animal tests done within two years.