MEMS Technologies for Energy Harvesting

The objective of this chapter is to introduce the technology of Microelectromechanical Systems, MEMS, and their application to emerging energy harvesting devices. The chapter begins with a general introduction to the most common MEMS fabrication processes. This is followed with a survey of design mechanisms implemented in MEMS energy harvesters to provide nonlinear mechanical actuations. Mechanisms to produce bistable potential will be studied, such as introducing fixed magnets, buckling of beams or using slightly slanted clamped-clamped beams. Other nonlinear mechanisms are studied such as impact energy transfer, or the design of nonlinear springs. Finally, due to their importance in the field of MEMS and their application to energy harvesters, an introduction to actuation using piezoelectric materials is given. Examples of energy harvesters found in the literature using this actuation principle are also presented

Energy Harvesting in a Coupled System Using Nonlinear Impact

Energy harvesting from broadband excitation, such as aircraft noise, and low frequency excitation, such as human motion, has gained significant interest recently. Vibro-impact is one of the methods used to improve capability of the harvester by low to high frequency conversion. The present paper analyses the effect of vibro-impact within a coupled beam system. The system is base excited and a localised non-linearity is induced at the point of impact. Modal reduction techniques are applied to reduce the computational time. The localisation effect on the coupled beam system is performed by varying the system parameters, for example the amplitude of excitation, the clearance and stiffness between the beams

A new S-shaped MEMS PZT cantilever for energy harvesting from low frequency vibrations below 30 Hz

10.1007/s00542-012-1424-1Microsystem Technologies184497-50

Kinetic energy harvesting

This chapter introduces principles of normal kinetic energy harvesting and adaptive kinetic energy harvesting. Kinetic energy harvesters, also known as vibration power generators, are typically, although not exclusively, inertial spring-mass systems. Electrical power is extracted by employing one or a combination of different transduction mechanisms. Main transduction mechanisms are piezoelectric, electromagnetic and electrostatic. As most vibration power generators are resonant systems, they generate maximum power when the resonant frequency of the generator matches ambient vibration frequency. Any difference between these two frequencies can result in a significant decrease in generated power. Recent development in adaptive kinetic energy harvesting increases the operating frequency range of such generators. Possible solutions include tuning resonant frequency of the generator and widening the bandwidth of the generator. In this chapter, principles and operating strategies for adaptive kinetic energy harvesters will be presented and compared