Design of autonomous micro-solar powered energy harvesting system for self-powered batteries-less wireless sensor mote

Harvesting electrical power from environment energy sources is an attractive and increasingly feasible option for several batteries-less micro-scale electronic systems such as biomedical implants and wireless sensor nodes that need to operate autonomously for long periods of time without needed batteries replacement and maintenance. However, designing highly efficient micro-scale energy harvesting systems requires an in-depth understanding of various design considerations and tradeoffs. This paper reports and describes method of power management circuit design and implementation for micro-scale solar energy harvesting that based-on step-up voltage conversion, DC-DC boost converter with maximum peak power controllable and minimum 300mV start-up input voltage. A micro-solar powered energy harvesting and power management system introduced for targeting to autonomous wireless sensor node (AWSN) application for monitoring purpose such as remote patient monitoring, structural monitoring and precision agriculture monitoring. In order to enhance efficiency of supply power to a microcontroller unit (MCU) and a radio frequency (RF) module in a battery-less sensor network device without battery power, our current prototype system utilizes combination of a super-capacitor with miniaturize flexible photovoltaic cells. Based on the consideration of practical application, we designed a communication mechanism for the battery-less wireless sensor mote network system and discuss the various challenges and considerations involved from a system-design perspective.