Just how giant is “giant” electrostriction?
A dielectric material deforms when an electric field is applied to it. This phenomenon, known as electrostriction, has applications in sensors and actuators. In 2012, a class of materials was discovered that exhibit “giant” electrostriction, which could expand the electromechanical applications of electrostriction.
Yu and Janolin reviewed how “giant” electrostriction differs from classical electrostriction, identifying examples from prior literature and comparing their characteristics and performance. They defined “giant” electrostrictors as materials that exhibit an electrostriction coefficient at least ten times larger than expected.
“We wanted to propose a definition of what ‘giant’ electrostriction is to help clarify the field,” said author Pierre-Eymeric Janolin. “We hope readers will adopt this definition and use it as a springboard to improve the understanding of this phenomenon.”
Many electromechanical applications currently use lead-based piezoelectrics instead of electrostrictors due to their superior performance. The authors believe “giant” electrostrictors may be able to replace these toxic piezoelectric materials in certain devices.
“While electrostriction has been overshadowed by piezoelectricity for electromechanical applications, it could be an eco-friendly, high-temperature, low-loss alternative for those applications,” Janolin said.
Before “giant” electrostriction can overtake piezoelectricity, however, the phenomenon must be studied more. Open questions remain, such as the mechanism underlying “giant” electrostriction. Although researchers suspect oxygen vacancies are a key component, its operation is not fully understood.
In addition to encouraging readers to answer these remaining questions, the authors hope their review inspires the discovery of new “giant” electrostrictors, the engineering of materials with enhanced “giant” electrostriction, and the design of devices based on this phenomenon.
Source: “Defining “giant” electrostriction,” by Jiacheng Yu and Pierre-Eymeric Janolin, Journal of Applied Physics (2022). The article can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0079510 .