Although they don’t do much for the environment if used in small quantities and for small-scale applications, piezoelectric generators are actually useful to study, because if applied to a larger extent they could provide us with a valuable source of energy.
Dr. Yong Shi, from Stevens Institute of Technology has released a paper called “1.6 V Nanogenerator for Mechanical Energy Harvesting Using PZT Nanofibers.” He uses piezoelectric nanowire- and nanofiber-based generators that can convert mechanical energy into electricity.
His approach uses PZT nanofibers having a diameter of 60 nm and a length of 500 nm, which are aligned on interleaved electrons of platinum wires. The generator comes packed using a soft polymer on a silicon substrate. The output is not pretty impressive at a first glance: 1.63 volts and 0.03 micro-watts. Though, with these amounts of energy you could successfully power implantable biosensors, pacemakers, and other small devices.
“One of the major limitations of current active implantable biomedical devices is that they are battery powered. This means that they either have to be recharged or replaced periodically. Dr. Shi’s group has demonstrated a technology that will allow implantable devices to recover some of the mechanical energy in flowing blood or peristaltic fluid movement in the GI tract to power smart implanable biomedical devices,” says, Dr. Arthur Ritter, Director of Biomedical Engineering at Stevens. “The fact that his technology is based on nano-structures makes possible power supplies for nano-robots that can exist in the blood stream for extended periods of time and transmit diagnostic data, take samples for biopsy and/or send images wirelessly to external data bases for analysis.”
Along with its use in medicine, the nanofiber piezoelectric generator could also use for in-asphalt power devices. Tens of millions of such devices throughout an asphalt of a length of some kilometers, for example, could power all the sensors and lighting needed on a highway, reducing the CO2 output.