Nuclear
batteries were tried successfully for some period. Practical nuclear
batteries use
plutonium (238Pu). It has a half-life of 87 years so the output degrades only by 11% in 10
years. However it is highly toxic and 1μg in the blood stream could be fatal. Early pacemakers
used metallic plutonium where as later ones used ceramic plutonium oxide. The plutonium
emits alpha particles, which impact upon the container and generate heat. Thermopiles of
dissimilar p- or n-doped bismuth telluride generate the electricity for the pacemaker circuits.
Though these nuclear power sources had very long life, they were large and created problems
when travelling between states and countries due to the presence of their radioactive fuel. They
also must be removed at the time of death and returned for proper disposal. Nuclear powered
pacemakers are no longer sold. but still a small number of implanted nuclear devices that
remain in use. Nuclear power sources became obsolete with the development of lithium batteries.
Also the long life is contributed to the low power requirements of the pacemaker.
If you know someone who has one of these and can leave it to you in their will, maybe you could try it. At this time I think the government keeps close tabs on all radioactive material.