duce system weight and volume, increase operating lifetime, The recent explosion in capability of embedded and portable decrease maintenance costs, and open new frontiers for inelectronics has not been matched by battery technology. tegrating digital computation with sensing and actuation. The slow growth of battery energy density has limited device Because wireless communication typically consumes much lifetime and added weight and volume. Passive energy har- more power than computation, many applications want to vesting from solar radiation, thermal sources, or mechanical maximize the amount of computation done at a particular vibration has potentially wide application in wearable and sensor network node [1]. Much current work is focused on embedded sensors to complement batteries. The amount of maximizing power generation by developing and optimizing energy from harvesting is typically small and highly variable, transducers for energy harvesting. However, the desire for requiring ci...