SEMI-LINEAR METAMATERIAL HYPERLENS FOR SUBWAVELENGTH IMAGING
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- 英文论文题名：SEMI-LINEAR METAMATERIAL HYPERLENS FOR SUBWAVELENGTH IMAGING
- 论文作者：Deng-ke GUO ; Geng-kai HU
- 英文论文作者：Deng-ke GUO ; Geng-kai HU ; Key Laboratory of Dynamics and Control of Flight Vehicle ; Ministry of Education ; School of Aerospace Engineering ; Beijing Institute of Technology
- 年：2016
- 作者机构：Key Laboratory of Dynamics and Control of Flight Vehicle, Ministry of Education, School of Aerospace Engineering, Beijing Institute of Technology;
- 英文论文关键词：Semi-linear material ; Hyperelastic transformation theory
- 会议召开时间：2016-10-21
- 会议录名称：2016年全国压电和声波理论及器件应用研讨会论文摘要集
- 英文会议录名称：Abstract Book of 2016 Symposium on Piezoelectricity, Acoustic Waves and Device Applications
- 语种：英文
- 分类号：TB34
- 学会代码：AGLU
- 会议名称：2016年全国压电和声波理论及器件应用研讨会
- 会议地点：中国陕西西安
- 主办单位：中国力学学会、中国声学学会、IEEE UFFC分会
- 学会名称：中国力学学会
- 页数：2
- 文件大小：9k
- 原文格式：D
- 会议级别：全国
摘要
Background, Motivation and Objective Manipulating evanescent waves with metamaterials to overcome the diffraction limit has received much attention in electromagnetics, and has been recently extended to acoustic waves for subwavelength ultrasonic sensing. The underlying mechanism is based on the hyperbolic dispersion of metamaterials. Li et al. has first demonstrated experimentally that acoustic magnifying hyperlens can be realized by extremely anisotropic structures with hyperbolic dispersion. Analogous elastic hyperlens has also been carried out by Lee et al, which consists of angularly alternating layers of metal and air. However, conventional hyperlens made of solid structures lacks the ability of shape adaption to irregular profiles of object under detection. In this work, we try to design a metamaterial hyperlens made of flexible semi-linear structures, which would resist large deformation while maintain the imaging characteristics. Statement of Contribution/Methods The challenge of the issue is to achieve the imaging-invariance property under large deformation. This can be accomplished by using hyperelastic transformation theory, in which material deformation is treated as a part of material property. It is found that the invariance can be kept in a semi-linear material. Based on the spring structure, we design a one-dimensional semi-linear material. The flexible elastic hyperlens is further designed and verified by numerical simulation. Results The semi-linear structures made of springs are analyzed in theory. Strain energy function of this structure shows identical results with the one of semi-linear materials. Effective stiffness satisfies the hyperelastic transformation relation in elastic case. Dispersion characteristics of the semi-linear structures are studied. It is found that the isofrequency contour is nearly flat, implying the complete conversion from evanescent to propagating waves as required by subwavelength imaging. Numerical simulation demonstrates that the subwavelength imaging performance is invariant to the large deformation of the surface profile of the hyperlens. Discussion and Conclusions Flexible solid hyperlens based on the semi-linear materials is designed. Numerical simulation verifies that the hyperlens is capable of shape adaption to irregular profiles of object under detection, as is superior to those proposed previously.
Background, Motivation and Objective Manipulating evanescent waves with metamaterials to overcome the diffraction limit has received much attention in electromagnetics, and has been recently extended to acoustic waves for subwavelength ultrasonic sensing. The underlying mechanism is based on the hyperbolic dispersion of metamaterials. Li et al. has first demonstrated experimentally that acoustic magnifying hyperlens can be realized by extremely anisotropic structures with hyperbolic dispersion. Analogous elastic hyperlens has also been carried out by Lee et al, which consists of angularly alternating layers of metal and air. However, conventional hyperlens made of solid structures lacks the ability of shape adaption to irregular profiles of object under detection. In this work, we try to design a metamaterial hyperlens made of flexible semi-linear structures, which would resist large deformation while maintain the imaging characteristics. Statement of Contribution/Methods The challenge of the issue is to achieve the imaging-invariance property under large deformation. This can be accomplished by using hyperelastic transformation theory, in which material deformation is treated as a part of material property. It is found that the invariance can be kept in a semi-linear material. Based on the spring structure, we design a one-dimensional semi-linear material. The flexible elastic hyperlens is further designed and verified by numerical simulation. Results The semi-linear structures made of springs are analyzed in theory. Strain energy function of this structure shows identical results with the one of semi-linear materials. Effective stiffness satisfies the hyperelastic transformation relation in elastic case. Dispersion characteristics of the semi-linear structures are studied. It is found that the isofrequency contour is nearly flat, implying the complete conversion from evanescent to propagating waves as required by subwavelength imaging. Numerical simulation demonstrates that the subwavelength imaging performance is invariant to the large deformation of the surface profile of the hyperlens. Discussion and Conclusions Flexible solid hyperlens based on the semi-linear materials is designed. Numerical simulation verifies that the hyperlens is capable of shape adaption to irregular profiles of object under detection, as is superior to those proposed previously.
Background, Motivation and Objective Manipulating evanescent waves with metamaterials to overcome the diffraction limit has received much attention in electromagnetics, and has been recently extended to acoustic waves for subwavelength ultrasonic sensing. The underlying mechanism is based on the hyperbolic dispersion of metamaterials. Li et al. has first demonstrated experimentally that acoustic magnifying hyperlens can be realized by extremely anisotropic structures with hyperbolic dispersion. Analogous elastic hyperlens has also been carried out by Lee et al, which consists of angularly alternating layers of metal and air. However, conventional hyperlens made of solid structures lacks the ability of shape adaption to irregular profiles of object under detection. In this work, we try to design a metamaterial hyperlens made of flexible semi-linear structures, which would resist large deformation while maintain the imaging characteristics. Statement of Contribution/Methods The challenge of the issue is to achieve the imaging-invariance property under large deformation. This can be accomplished by using hyperelastic transformation theory, in which material deformation is treated as a part of material property. It is found that the invariance can be kept in a semi-linear material. Based on the spring structure, we design a one-dimensional semi-linear material. The flexible elastic hyperlens is further designed and verified by numerical simulation. Results The semi-linear structures made of springs are analyzed in theory. Strain energy function of this structure shows identical results with the one of semi-linear materials. Effective stiffness satisfies the hyperelastic transformation relation in elastic case. Dispersion characteristics of the semi-linear structures are studied. It is found that the isofrequency contour is nearly flat, implying the complete conversion from evanescent to propagating waves as required by subwavelength imaging. Numerical simulation demonstrates that the subwavelength imaging performance is invariant to the large deformation of the surface profile of the hyperlens. Discussion and Conclusions Flexible solid hyperlens based on the semi-linear materials is designed. Numerical simulation verifies that the hyperlens is capable of shape adaption to irregular profiles of object under detection, as is superior to those proposed previously.
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