Near-perpetual operated solar and RF powered autonomous sensing systems

The energy supply has for long been one of the most severe throttling parameters in Wireless Sensor Networks, rendering the renewable environmental energy, such as solar or RF, a very attractive power source for these networks. The optimal design of WSN nodes involves not only theoretic designs and approaches but also developing working prototypes. In this abstract we are presenting some of the state-of-the-art, energyefficient and nearly perpetually powered wireless sensor nodes existent. The energy harvested by these nodes comes from either the solar or the RF power.