Читать книгу Vibrations of Linear Piezostructures - Andrew J. Kurdila - Страница 17

While small piezoelectric specimens typically to do not output large currents or power, they can generate very high voltage differences under application of stress. It is for this reason that piezoelectric igniters are commonly used in gas broilers, gas stoves and ranges, gas fireplaces, or other appliances. The igniters usually operate by releasing a spring loaded switch that impacts the piezoelectric specimen, thereby generating a large, transient potential difference [36]. Such a voltage is high enough that it induces current flow across a gap that ignites the gas. In addition, the use of piezoelectric transducers in energy harvesting applications is a rapidly growing field. See for example [14] and the references therein for a good, comprehensive technical treatment of this topic. As noted before, while small piezoelectric transducers usually are not appropriate as large supplies of power, they are well suited to applications that require local, modular, or isolated energy sources for microscale electromechanical (MEMs) devices. Often, classes of sensors require small sources of energy to perform their associated measurements, and piezoelectric transducers have proven to be a viable route to support such sensors. There are numerous studies of energy reclamation from a wide range of sources [14]. Examples of composite piezoelectric structures that are connected to linear, ideal, passive electrical networks are studied in Chapters 6, 7, and 8. These electromechanical models are also suitable for the study of nonlinear switching strategies for energy harvesting. The emerging field of MEMs or NEMs (nanoelectromechanical systems) robotics requires microscale energy supplies to enable their mobility, and piezoelectric transducers are often the choice to develop self‐contained MEMs robots.