Ultra-large electromechanical deformation in lead-free piezoceramics at reduced thickness

Xiang He; Muzaffar Ahmad Boda; Chen Chen; Rongmin Dun; Lu Wang; Yizheng Bao; Dongfang Pang; Lin Guo; Huarong Zeng; Yongxiang Li; Zhiguo Yi

doi:10.1039/d3mh01657a

Ultra-large electromechanical deformation in lead-free piezoceramics at reduced thickness

Mater Horiz. 2024 Feb 19;11(4):1079-1087. doi: 10.1039/d3mh01657a.

Authors

Xiang He^{1

2

3}, Muzaffar Ahmad Boda¹, Chen Chen¹, Rongmin Dun^{1

2

3}, Lu Wang^{1

2}, Yizheng Bao¹, Dongfang Pang⁴, Lin Guo³, Huarong Zeng^{1

2}, Yongxiang Li⁵, Zhiguo Yi^{1

2

3}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China. zhiguo@mail.sic.ac.cn.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
³ CAS Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. zhiguo@fjirsm.ac.cn.
⁴ College of Rare Earths, Jiangxi University of Science and Technology, Ganzhou 341000, China.
⁵ School of Engineering, RMIT University, Melbourne, VIC 3000, Australia.

PMID: 38093683
DOI: 10.1039/d3mh01657a

Abstract

Lead-free piezoceramics with large controllable deformations are highly desirable for numerous energy converter applications ranging from consumer electronics to medical microrobots. Although several new classes of high-performance ferroelectrics have been discovered, a universal strategy to enable various piezoceramics to realize large electromechanical deformations is still lacking. Herein, by gradually reducing the thickness from 0.5 mm to 0.1 mm, we discover that a large nominal electrostrain of ∼11.49% can be achieved in thin 0.937(Bi_0.5Na_0.5)TiO₃-0.063BaTiO₃ (BNT-BT) ceramics with highly asymmetric strain-electric field curves. Further analyses of the polarization switching process reveal that the boosted strain curves originate from the bending deformation driven by asymmetric ferroelastic switching in the surface layers. Based on this, one monolayer BNT-BT was designed to realize digital displacement actuation and a scanning mirror application with a maximum mirror deflection angle of 44.38°. Moreover, the surface effect-induced bending deformation can be extended to other piezoceramics, accompanied by derived shape retention effects. These discoveries raise the possibility of utilizing thickness engineering to design large-displacement actuators and may accelerate the development of high-performance lead-free piezoceramics.