Designing electromechanical metamaterial with full nonzero piezoelectric coefficients

Area of Science:

• Materials Science and Engineering
• Metamaterials
• Piezoelectric Ceramics

Background:

• Designing metamaterials with unusual properties, like negative or ultrahigh parameters, remains challenging, especially for multiphysics coupling materials.
• Natural piezoelectric ceramics have limited nonzero elements in their piezoelectric matrix, hindering advanced device applications.

Purpose of the Study:

• To introduce a novel methodology for creating artificial anisotropy in metamaterials.
• To overcome the inherent limitations of natural piezoelectric materials by enabling all nonzero piezoelectric matrix elements.
• To achieve tunable and ultrahigh effective piezoelectric coefficients.

Main Methods:

• Inspired by quasi-symmetry breaking, a metamaterial design approach was employed.
• Topological structures and geometrical dimensions of unit elements were meticulously programmed.
• Theoretical and experimental validations were conducted.

Main Results:

• Demonstrated the ability to excite all nonzero piezoelectric matrix elements, unlike in natural materials.
• Achieved tunable nonzero and ultrahigh effective piezoelectric coefficients.
• Successfully validated the design principle both theoretically and experimentally.

Conclusions:

• The proposed metamaterial design methodology effectively generates unnatural piezoelectric parameters in ceramics.
• This approach offers a pathway to overcome limitations in natural piezoelectric materials.
• The design principle is potentially applicable to other multiphysics coupling metamaterials.