Conceptual Design of GaN Betavoltaic Battery using in Cardiac Pacemaker

Pacemaker is an electronic biomedical device which stimulates and regulates or amplify the human heartbeat by delivering weak electrical pulses to the cardiac muscle at regular intervals when its natural regulating mechanisms break down. The purpose of the present work is to introduce a kind of low power Betavoltaic battery using in nuclear powered cardiac pacemakers which have higher efficiency than those available with previous devices. In this design, two p-n diode structures from GaN semiconductor were used to collect the charge from a layer of 63Ni as a source which is centered between the two p-n junctions. MCNP simulation results have been used to determine the amount of electron current from interaction of beta particles in p-n junctions. Calculation results indicate that the short circuit current, open circuit voltage and efficiency of a single device are 1.1 µA/cm2, 2.7 volt and 25%, respectively. Also, it's concluded that with suitable arrangement of these single devices, one could construct a battery with required current, voltage and power for this application