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Flexoelectricity refers to the mechanical-electro coupling between strain gradient and electric polarization, and conversely, the electro-mechanical coupling between electric field gradient and mechanical stress. This unique effect shows a promising size effect which is usually large as the material dimension is shrunk down. Moreover, it could break the limitation of centrosymmetry, and has been found in numerous kinds of materials which cover insulators, liquid crystals, biological materials, and semiconductors. In this review, we will give a brief report about the recent discoveries in flexoelectricity, focusing on the flexoelectric materials and their applications. The theoretical developments in this field are also addressed. In the end, the perspective of flexoelectricity and some open questions which still remain unsolved are commented upon.


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Flexoelectric materials and their related applications: A focused review

Show Author's information Longlong SHUa,b( )Renhong LIANGaZhenggang RAOa,bLinfeng FEIa,bShanming KEa,b( )Yu WANGa,b
School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China
Jiangxi Key Laboratory for Two-dimensional Materials and Devices, and Jiangxi Engineering Laboratory for Advanced Functional Thin Films, Nanchang University, Nanchang 330031, China

Abstract

Flexoelectricity refers to the mechanical-electro coupling between strain gradient and electric polarization, and conversely, the electro-mechanical coupling between electric field gradient and mechanical stress. This unique effect shows a promising size effect which is usually large as the material dimension is shrunk down. Moreover, it could break the limitation of centrosymmetry, and has been found in numerous kinds of materials which cover insulators, liquid crystals, biological materials, and semiconductors. In this review, we will give a brief report about the recent discoveries in flexoelectricity, focusing on the flexoelectric materials and their applications. The theoretical developments in this field are also addressed. In the end, the perspective of flexoelectricity and some open questions which still remain unsolved are commented upon.

Keywords:

flexoelectricity, strain gradient, electric polarization, dielectric constant, liquid crystals, sensors and actuators
Received: 05 December 2018 Accepted: 08 December 2018 Published: 13 June 2019 Issue date: June 2019
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Publication history
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Acknowledgements
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Publication history

Received: 05 December 2018
Accepted: 08 December 2018
Published: 13 June 2019
Issue date: June 2019

Copyright

© The author(s) 2019

Acknowledgements

This work was supported by the National Natural Science Foundation of China under Grant Nos. 11574126 and 11604135, and partly by the Natural Science Foundation of Jiangxi Province (No. 20161BAB216110), China Postdoctoral Science Foundation (No. 2017M612162), and Postdoctoral Science Foundation of Jiangxi Province (No. 2017KY02).

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