Abstract
The use of electronic devices is an integral part of our everyday life and a
major part of our activities with these devices is related to receiving, sending, and
storing information. Some of these devices used for sensing, analysing, and
transmitting signals require a very small amount of energy. An alternative source to
power these devices could be through harvesting tiny mechanical motions associated
with different types of motions. Nanogenerators (NG) are potential sources of energy
harvesting by converting waste mechanical energies into useful electrical energy. NGs
have already been commercialized in the health and automobile industry as pacemakers
and tyre pressure monitoring systems, respectively. However, there is a wide scope of
using them for common household and environment remediation applications, which is
currently restricted due to the high cost of fabrication and low energy conversion
efficiency. Vibrational energy associated with wind, flow of fluid, body movements,
roads, train tracks, etc. can be converted to power devices locally and reduce the carbon
footprint due to the energy produced by fossil fuels. This book chapter reviews the
basic working of different nanogenerators based on piezoelectricity, triboelectricity
pyroelectric, and flexoelectricity. Many non-lead-containing piezoelectric materials are
promising candidates for piezoelectric nanogenerators (PENG) that can also be used for
various self-powered electronic and biomedical devices. Many metal-oxides such as
zinc-oxides and hafnium-oxides could be of special interest to this. Triboelectricnanogenerators (TENG) could be the most preferred device for harvesting water-wave
blue-energy and integration with conventional electromagnetic-induction (generators)
that can be deployed at a large-scale.