How to get the lead out of electronics

U. LEEDS (UK) — A new manmade material could potentially replace lead-based ceramics in electronics ranging from digital cameras to ultrasound scanners.

European regulations now bar the use of most lead-containing materials in electronic and electrical devices. Ceramic crystals known as “piezoelectrics” are currently exempt from these regulations but this may change in the future, owing to growing concerns over the disposal of lead-based materials.

Piezoelectric materials generate an electrical field when pressure is applied, and vice-versa. In gas igniters on ovens and fires, for example, piezoelectric crystals produce a high voltage when they are hit with a spring-loaded hammer, generating a spark across a small gap that lights the fuel.

Researchers at the University of Leeds used a high-intensity X-ray beam to show how a simple, lead-free ceramic could potentially do the same job as zirconium titanate, or PZT, the most common piezoelectric material. The results of the work are published in the journal Applied Physics Letters.

“PZT is the best material for the job at the moment, because it has the greatest piezoelectric effect, good physical durability, and can be radically tailored to suit particular applications,” says Adam Royles, PhD student on the project. “The lead-free ceramic that we have been studying is lightweight and can be used at room temperature. This could make it an ideal choice for many applications.”

In the medical field, PZT is used in ultrasound transducers, where it generates sound waves and sends the echoes to a computer to convert into a picture. Piezoelectric ceramics also hold great potential for efficient energy harvesting, a possible solution for a clean sustainable energy source in the future.

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