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2025 , Vol. 1 >Issue 4: 300 - 317

DOI: https://doi.org/10.1007/s44275-024-00019-8

Original Article

Optimizing bendability of flexible electronic devices using a neutral layer strategy

  • Majiaqi Wu ,
  • Maoliang Jian ,
  • Jianhua Zhang ,
  • Lianqiao Yang
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  • 1. School of Microelectronics, Shanghai University, Shanghai, 201800, China;
    2. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai, 200072, China

Received date: 2024-09-02

  Revised date: 2024-11-21

  Accepted date: 2024-11-26

  Online published: 2025-01-08

Supported by

This research was financially supported by the Natural Science Foundation, China (Grant No. 52175512) and Huawei Technologies Co., Ltd.

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Abstract

The neutral layer (NL) strategy is a key technique for improving the bendability of flexible electronic devices. In this study, by considering a three-layer structure as an example, the results obtained by finite element analysis (FEA) showed that the NL gradually moved to the top surface of the film as the film thickness and Young’s modulus increased, which are similar to the results produced by theoretical calculations. Subsequently, we optimized the thickness of a single NL structure and the failure bending radius of an indium tin oxide (ITO) electrode was reduced by 50% after optimization. In order to address the problems that affect the design of a single NL, we used optical clear adhesive (OCA) to generate multiple NLs. The FEA method was again applied to the structure and the results showed that decreasing the elastic modulus of the OCA and film thickness could reduce the maximum strain in the film. Finally, the effects of the OCA parameters on the protection of a multiple-layer ITO electrode structure were verified in bending experiments, which showed that the strain on ITO could be reduced from 5.6% to almost 0 in the two-electrode structure. The proposed strategies for designing single and multiple NLs can provide some guidance to facilitate optimizing the electronic infrastructure of flexible devices.

Key words： Flexible electronic devices; Thickness optimization design; Multiple neutral layers; Mechanical simulation

Cite this article

Majiaqi Wu , Maoliang Jian , Jianhua Zhang , Lianqiao Yang . Optimizing bendability of flexible electronic devices using a neutral layer strategy[J]. Moore and More, 2025 , 1(4) : 300 -317 . DOI: 10.1007/s44275-024-00019-8

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