Principles and Applications of Ubiquitous Sensing

Chapter 10Energy Harvesting

The sensing and design principles we considered so far can have another and crucial application, which is the harvesting of energy from the environment to power the sensors themselves. You may recall that in Chapter 1 I defined sensors as devices that transform one form of energy to another (often to electrical energy). You can see that I have already acknowledged that the environment in which sensors are deployed produces energy that can be used to operate sensors by charging their batteries or energy storage devices. Some environments, such as the human body, produce heat and movement. Researchers have identified several mechanisms by which electrical energy can be harvested from a human body including: use of glucose oxidation, electric potentials of the inner ear, mechanical movements of limbs, and natural vibrations of internal organs (Mitcheson et al. 2008; Ramadass and Chandrakasan 2010; Saha et al. 2008; Vullers et al. 2009). Bridges and water produce continuous ambient movement (vibration) (Beeby et al. 2006, 2007; Stephen 2006); other environments such as open fields, give the opportunity to use solar and wind energy (Kansal et al. 2007; Raghunathan et al. 2005; Sudevalayam and Kulkarni 2011; Taneja et al. 2008). Thermocouples can be used to generate energy from heat (Tan and Panda 2011), piezoelectric devices can be used to generate energy from vibration (Erturk and Inman 2011; Khaligh et al. 2010; Sirohi and Mahadik 2011; Stanton et al. ...