Getting The Awful, Yet Practically Essential Lead Out of Gadgets
Lead ingots via Wikipedia
Lead is unfortunately an important component in electronics, especially when it comes to piezoelectronics. We're mostly familiar with piezoelectricity when it comes to concept devices - things that can generate a charge based on pressure being applied to them. But it is used in a lot of common gadgets, such as phones with touch screens. But the best compounds for piezoelectricity are lead-based, and lead is something we all want to see phased out of electronics. Researchers are now working on how to get lead out of gadgets, and have found one promising replacement for the dangerous metal. According to Scientific American, researchers at UC Berkeley have been experimenting with bismuth ferrite, a substance that hasn't shown much promise as a replacement for lead since it can't really produce enough voltage...until now.
"By experimenting with bismuth ferrite films of different thicknesses grown on different types of substrates, [the research team lead by Robert] Zeches was able to create a film that could generate more piezoelectric "strain"--measured in terms of charge generated--than previously possible. ... As strain is increased more electricity is produced by the piezoelectric effect. "Robert took a big step forward by finding the right combination of bismuth ferrite crystal shapes to boost the amount of strain produced," Ramesh says."
While it is too soon to say if bismuth ferrite-based substances can replace lead entirely, there is potential, and the researchers are now working on figuring out which variables to tweak to maximize the film's piezoelectric potential.
Last year we also heard about the potential of bismuth samarium ferrite (BSFO) as an alternative for lead in electronics, which could be first commercial replacement for the lead used in transducers, actuators, and sensors. As for bismuth ferrite-based substances, we'll likely first see them in nanoscale data storage devices.
With more experimentation, we may just find a far less toxic replacement for lead, which could go a long way in reducing e-waste's toxic impact.
More on Lead in Gadgets
Ditching Lead: Breakthrough Material Helps Us Minimize Lead in Electronics
Toxic Travelling: Lead's Vicious Circle
BEST Battery Program Aims to Reduce Lead Battery Poisoning in Asia