Researchers have developed a new technique that allows the restoration of piezoelectric materials used in ultrasound and sonar technologies at room temperature, simplifying repairs and enabling continuous use without the need for disassembly. This method not only enhances the durability and efficiency of these devices but also opens up possibilities for advancements in ultrasound technology. Credit: SciTechDaily.com

A new technique developed by researchers enables the restoration of crucial properties in piezoelectric materials at room temperature, streamlining repairs and extending the lifespan of ultrasound and sonar devices.

Heat and pressure can degrade the properties of piezoelectric materials essential for advanced ultrasound and sonar technologies. Traditionally, repairing this damage has involved disassembling the devices and exposing the materials to even higher temperatures. Now, researchers have developed a technique to restore these properties at room temperature, simplifying the repair process and paving the way for new ultrasound technologies.

Piezoelectric materials have many applications, including sonar technologies and devices that generate and sense ultrasound waves. But for these devices to efficiently generate sonar or ultrasound waves, the material needs to be “poled.”

That’s because the piezoelectric materials used for sonar and ultrasound applications are mostly ferroelectric. And like all ferroelectric materials, they exhibit a phenomenon called spontaneous polarization. That means they contain pairs of positively and negatively charged ions called dipoles. When a ferroelectric material is poled, that means all of its dipoles have been pulled into alignment with an external electric field. In other words, the dipoles are all oriented in the same direction, which makes their piezoelectric properties more pronounced.

Challenges in Maintaining Material Alignment

“If those dipoles aren’t in alignment it’s difficult to generate targeted ultrasound waves with the amplitude needed for them to be practical,” says Xiaoning Jiang, corresponding author of a paper on the work and Dean F. Duncan Distinguished Professor of Mechanical and Aerospace Engineering at SciTechDaily