2008 DEC 1 -- Researchers at the University of Maryland's A. James Clark School of Engineering have discovered a new lead-free material, bismuth samarium ferrite (BSFO), for use in products ranging from biomedical imaging devices to airbag sensors to inkjet printers. If implemented commercially, it could replace a common lead-based material found in these and other electronic devices, keeping lead out of landfills and the ecosystem.
"One of the reasons it's so hard to let go of lead is because it's so useful," explained Ichiro Takeuchi, associate professor in the Clark School's Department of Materials Science and Engineering. "Its properties make it ideal for use in electronic devices."
According to the Environmental Protection Agency, U.S. households threw out more than 300 million electronic devices in 2006, many of which were exported to other countries for recycling, where their lead components were improperly disposed of [1]. When the U.S. moves to digital-only broadcasting in early 2009, thousands of older, lead-containing analog TV sets could end up in landfills around the world as well.
While manufacturers have developed replacements for lead in many products, until now no commercial replacement existed for lead zirconate titanate (Pb(Zr,Ti)O3, or PZT) -- the material of choice for transducers, actuators, sensors, and microelectromechanical systems used in common electronic devices.
PZT is more than 40 percent lead, but it also has piezoelectric properties, which means it acts like a switch -- it can either create a voltage when mechanical stress is applied to it, or it can deform its shape when voltage is applied. This behavior is used to create actuators, moving components in electronic devices that translate electrical input into motion to accomplish mechanical tasks, such as controlling the inkjet nozzles on a printer.
Takeuchi and his collaborators at the University of Maryland's Keck Laboratory for Combinatorial Nanosynthesis and Multiscale Characterization have created the new piezoelectric material, which in addition to enhanced piezoelectric properties can operate at higher temperatures and is easier to make than other proposed lead-free alternatives. These qualities make it a good candidate for a PZT replacement.
The discovery of the new BSFO compound was introduced in a recent issue of Applied Physics Letters. A provisional patent has been filed for the material.
Keywords: A. James Clark School of Engineering, Bioengineering, Biomedical Engineering, Biomedicine.
This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2008, Biotech Business Week via NewsRx.com.
