Peter Cabauy, chief operating officer of City Labs, shows off the commercially-viable betavoltaic power supply developed by his company, Tuesday, July 10, 2012, in Homestead. The power cell generates electricity using a layer of the radioactive-element tritium mounted onto a semiconductor and can supply energy for several years without maintenance. Applications include biotechnological implants such as pacemakers as well as other hard to access devices in industry and defense. DANIEL BOCK / FOR THE MIAMI HERALD

Jesse Grant, engineer for City Labs, left, and Peter Cabauy, chief operating officer for the company, show off the commercially-viable betavoltaic power supply they have developed, Tuesday, July 10, 2012, in Homestead. The power cell generates electricity using a layer of the radioactive-element tritium mounted onto a semiconductor and can supply energy for several years without maintenance. Applications include biotechnological implants such as pacemakers as well as other hard to access devices in industry and defense. DANIEL BOCK / FOR THE MIAMI HERALD