Body Sensor Networking, Design and Algorithms

12Energy Harvesting Enabled Body Sensor Networks

12.1 Introduction

Wireless and embedded systems are commonly powered using batteries and, over time, there has been advances in creating low-power and energy-efficient systems to enable running for a longer time while consuming less energy. For applications where the system is expected to operate for longer, energy becomes a severe bottleneck and much research effort needs to be spent on the efficient use of battery energy while creating new technologies. Recently, another alternative, namely harvesting energy from the environment, has been explored to supplement or even replace batteries.

Sensor networks typically are required to run for a long time, often several years, and are only powered by batteries. This makes energy awareness a major issue when designing these networks. Finite battery capacity is therefore a limitation in the battery-powered networks. This consequently limits the lifetime of the wireless sensor network (WSN) applications or additional cost and complexity to regularly change the batteries. On the other hand, depleted batteries constitute environmental pollution and hazards.

While the technology in battery design is constantly improving and the power requirement of electronics is also dropping, they are not keeping pace with the increasing energy demands of many WSN applications. Therefore, there has been considerable interest in the development of systems capable of extracting sufficient electrical energy ...