双层薄膜与弹性梯度基底三层结构表面失稳分析  

Instability analysis of bi-layer films bonded to elastic graded substrate subjected to a compressive force

作　　者：许超 王博[1] 毕皓皓 师岩[3] 邓子辰[1,4] XU Chao;WANG Bo;BI Haohao;SHI Yan;DENG Zichen(Department of Engineering Mechanics,Northwestern Polytechnical University,710072 Xi'an,China;Department of Applied Mathematics,Northwestern Polytechnical University,710072 Xi'an,China;State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics&Astronautics,210016 Nanjing,China;Ministry of Industry and Information Technology Key Laboratory of Dynamics and Control of Complex Systems,Northwestern Polytechnical University,710072 Xi'an,China)

机构地区：[1]西北工业大学工程力学系,西安710072 [2]西北工业大学应用数学系,西安710072 [3]南京航空航天大学机械结构力学及控制国家重点实验室,南京210016 [4]西北工业大学复杂系统动力学与控制工信部重点实验室,西安710072

出　　处：《应用力学学报》2023年第1期154-161,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.11802319);机械结构力学及控制国家重点实验室开放课题资助项目(No.MCMS-E-0221K01)。

摘　　要：硬薄膜/软基底结构的表面失稳问题一直是柔性电子器件的难题,基于此,本文考虑了双层结构与弹性梯度基底间的界面剪切力,建立了双层薄膜/弹性梯度基底模型;利用位移协调条件,理论推导得到了双层薄膜/弹性梯度基底结构的临界应变和失稳波长的表达式并通过有限元仿真,验证了本研究解析解的有效性。在此基础上,应用此解析解进一步研究了弹性梯度基底的材料、双层薄膜结构厚度比等参数对临界应变和波长的影响。结果表明:减小器件层的厚度或者增加封装层的厚度,可以提高双层膜/弹性梯度基底结构的稳定性;当弹性梯度材料基底表面“较软”或器件层“较硬”时,器件层与基底界面的剪切力的影响较大,可以提升三层膜/基结构抵抗界面破坏的能力。本研究成果将为硬薄膜/弹性梯度基底结构的柔性电子器件的制备提供理论支撑。Surface instability of hard films adhered on soft substrate has always been a difficult problem for flexible electronic devices.Considering the shear stress between the bi-layer film and the elastic graded substrate,an analytical model of bi-layer film/elastic graded substrate is established.By using the displacement continuity of the interface,the analytical expressions of the critical strain and wavelength of the bi-layer film/elastic graded substrate are obtained.Then,through several examples,the validities of the proposed expressions are verified which are compared with those results obtained by the finite element analysis.At the same time,the influences of the geometric parameters of the bi-layer film and physical parameters of the elastic graded substrate on the buckling behavior are analyzed.The results in this paper show that decreasing the thickness of device layer or increasing the thickness of encapsulation layer can improve the stability of bilayer film/elastic graded substrate structure;if the substrate is relatively“soft”or the device layer is“hard”,the shear force of the interface between the device layer and the substrate will be taken into account,which can prevent the resistance of the three-layer film/substrate structure from undergoing interface failure.Above all,the research will provide theoretical support for the fabrication of flexible electronic devices with hard film/elastic graded substrate structure.

关 键 词：双层薄膜/弹性梯度基底结构 屈曲理论 临界应变 柔性电子 

分 类 号：TB301[一般工业技术—材料科学与工程]