High-performance lead-free ultrasonic devices for high-power applications

High-power ultrasonic devices are widely used in industry, ranging from the ultrasonic transducers for cleaning, welding, machining, additive manufacturing, metal forming, to the ultrasonic motors for positioning stages and robotics. Piezoelectric materials are the driving sources of those devices.

Since 1950s, lead zirconate titanate (PZT) has been the dominating material for ultrasonic devices, due to its excellent piezoelectric properties and mature fabrication techniques.

However, PZT contains a high content of lead (~60% in mass), which causes severe environmental issues and is consequently on EU’s Restriction of Hazardous Substances (RoHS) Directive list of materials to be phased out.

Developing high-power ultrasonic devices driven by lead-free piezoelectric materials is therefore crucial.The development of lead-free piezoelectric materials has made significant progress in recent years in both academia and industry, and their piezoelectric properties have now become comparable to those of PZT.

Together with our collaborators in Japan, in this project, we will develop high-performance high-power ultrasonic devices driven by lead-free piezoelectric materials to replace those driven by PZT.

The ultrasonic devices we deal with are Langevin transducers, ultrasonic motors, and high-power ultrasonic transducers at MHz frequencies. The aim is to achieve device performance that meets industrial standards with lead-free piezoelectric materials.