You probably learned in high school what the piezoelectric effect is: a phenomenon where an electromotive force is generated by applying mechanical stress to a material.
So far, piezoelectric devices used a material called lead zirconate titanate (PZT). However, PZT is expensive and contains lead, which is bad for the environment.
Progress does happen, though, as researchers from the Tsinghua University in China have developed a new type of piezoelectric material that doesn’t contain lead and is much cheaper to make.
They used zinc oxide (ZnO) foil and added vanadium (V), and got a material that starts to rival PZT.
To get a clearer picture of their finding, let’s define the piezoelectric effect through a variable named “d33,” measured in picoCoulombs/Newton (pC/N). Well, the d33 for PZT ranges from 400 to 2,200 pC/N and the d33 for the vanadium-enriched ZnO is 170 pC/N, versus the non-vanadium version of only 9.9 to 12.4 pC/N.
Piezoelectricity is already being used to capture vibrations from highways, railroads and other sources to power everything from sensors to billboards and street lighting.
Finding a better, more environmentally-friendly material than the standard one containing lead is a huge leap forward for this technology.
[via nikkei]
