Pervasive power: a radioisotope-powered piezoelectric generator. - Amit Lal; Rajesh Duggirala; Hui Li (IEEE Pervasive Comput., 2005)

Active circuits for ultra-high efficiency micropower generators using nickel-63 radioisotope. - Rajesh Duggirala; Hui Li; Amit Lal (ISSCC, 2006)