Publications
1.
Wang, Pai; Zheng, Yue; Fernandes, Matheus C.; Sun, Yushen; Xu, Kai; Sun, Sijie; Kang, Sung Hoon; Tournat, Vincent; Bertoldi, Katia
Harnessing Geometric Frustration to Form Band Gaps in Acoustic Channel Lattices Journal Article
In: Physical Review Letters, vol. 118, pp. 084302, 2017.
@article{Wang2017,
title = {Harnessing Geometric Frustration to Form Band Gaps in Acoustic Channel Lattices},
author = {Pai Wang and Yue Zheng and Matheus C. Fernandes and Yushen Sun and Kai Xu and Sijie Sun and Sung Hoon Kang and Vincent Tournat and Katia Bertoldi},
url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.084302},
doi = {10.1103/PhysRevLett.118.084302},
year = {2017},
date = {2017-02-21},
journal = {Physical Review Letters},
volume = {118},
pages = {084302},
abstract = {We demonstrate both numerically and experimentally that geometric frustration in two-dimensional periodic acoustic networks consisting of arrays of narrow air channels can be harnessed to form band gaps (ranges of frequency in which the waves cannot propagate in any direction through the system). While resonant standing wave modes and interferences are ubiquitous in all the analyzed network geometries, we show that they give rise to band gaps only in the geometrically frustrated ones (i.e., those comprising of triangles and pentagons). Our results not only reveal a new mechanism based on geometric frustration to suppress the propagation of pressure waves in specific frequency ranges but also open avenues for the design of a new generation of smart systems that control and manipulate sound and vibrations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We demonstrate both numerically and experimentally that geometric frustration in two-dimensional periodic acoustic networks consisting of arrays of narrow air channels can be harnessed to form band gaps (ranges of frequency in which the waves cannot propagate in any direction through the system). While resonant standing wave modes and interferences are ubiquitous in all the analyzed network geometries, we show that they give rise to band gaps only in the geometrically frustrated ones (i.e., those comprising of triangles and pentagons). Our results not only reveal a new mechanism based on geometric frustration to suppress the propagation of pressure waves in specific frequency ranges but also open avenues for the design of a new generation of smart systems that control and manipulate sound and vibrations.
2.
Zárate, Yair; Babaee, Sahab; Kang, Sung H.; Neshev, Dragomir N.; Shadrivov, Ilya V.; Bertoldi, Katia; Powell, David A.
Elastic metamaterials for tuning circular polarization of electromagnetic waves Journal Article
In: Scientific Reports, vol. 6, pp. 28273, 2016.
@article{Zárate2016,
title = {Elastic metamaterials for tuning circular polarization of electromagnetic waves},
author = {Yair Zárate and Sahab Babaee and Sung H. Kang and Dragomir N. Neshev and Ilya V. Shadrivov and Katia Bertoldi and David A. Powell},
url = {http://www.nature.com/articles/srep28273},
doi = {doi:10.1038/srep28273},
year = {2016},
date = {2016-06-20},
journal = {Scientific Reports},
volume = {6},
pages = {28273},
abstract = {Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.
3.
Shan, Sicong; Kang, Sung Hoon; Wang, Pai; Qu, Cangyu; Shian, Samuel; Chen, Elizabeth R.; Weaver, James C.; Bertoldi, Katia
Harnessing Multiple Folding Mechanisms in Soft Periodic and Porous Structures to Design Highly Tunable Phononic Crystals Journal Article
In: Advanced Functional Materials, vol. 24, pp. 4935–4942, 2014.
@article{Shan2014,
title = {Harnessing Multiple Folding Mechanisms in Soft Periodic and Porous Structures to Design Highly Tunable Phononic Crystals},
author = {Sicong Shan and Sung Hoon Kang and Pai Wang and Cangyu Qu and Samuel Shian and Elizabeth R. Chen and James C. Weaver and Katia Bertoldi},
url = {http://onlinelibrary.wiley.com/doi/10.1002/adfm.201400665/abstract},
year = {2014},
date = {2014-08-20},
journal = {Advanced Functional Materials},
volume = {24},
pages = {4935–4942},
abstract = {Mechanical instabilities in periodic porous elastic structures may lead to the formation of homogeneous patterns, opening avenues for a wide range of applications that are related to the geometry of the system. This study focuses on an elastomeric porous structure comprising a triangular array of circular holes, and shows that by controlling the loading direction, multiple pattern transformations can be induced by buckling. Interestingly, these different pattern transformations can be exploited to design materials with highly tunable properties. In particular, these results indicate that they can be effectively used to tune the propagation of elastic waves in phononic crystals, enhancing the tunability of the dynamic response of the system. Using a combination of finite element simulations and experiments, a proof-of-concept of the novel material is demonstrated. Since the proposed mechanism is induced by elastic instability, it is reversible, repeatable, and scale-independent, opening avenues for the design of highly tunable materials and devices over a wide range of length scales.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mechanical instabilities in periodic porous elastic structures may lead to the formation of homogeneous patterns, opening avenues for a wide range of applications that are related to the geometry of the system. This study focuses on an elastomeric porous structure comprising a triangular array of circular holes, and shows that by controlling the loading direction, multiple pattern transformations can be induced by buckling. Interestingly, these different pattern transformations can be exploited to design materials with highly tunable properties. In particular, these results indicate that they can be effectively used to tune the propagation of elastic waves in phononic crystals, enhancing the tunability of the dynamic response of the system. Using a combination of finite element simulations and experiments, a proof-of-concept of the novel material is demonstrated. Since the proposed mechanism is induced by elastic instability, it is reversible, repeatable, and scale-independent, opening avenues for the design of highly tunable materials and devices over a wide range of length scales.
4.
Shim, Jongmin; Shan, Sicong; Kosmrlj, Andrej; Kang, Sung Hoon; Chen, Elizabeth R.; Weaver, James C.; Bertoldi, Katia
Harnessing Instabilities for Design of Soft Reconfigurable Auxetic/Chiral Materials Journal Article
In: Soft Matter, vol. 9, pp. 8198-8202, 2013, (Highlighted on the Soft Matter blog.).
@article{Shim2013,
title = {Harnessing Instabilities for Design of Soft Reconfigurable Auxetic/Chiral Materials},
author = {Jongmin Shim and Sicong Shan and Andrej Kosmrlj and Sung Hoon Kang and Elizabeth R. Chen and James C. Weaver and Katia Bertoldi},
url = {http://pubs.rsc.org/en/content/articlelanding/2013/sm/c3sm51148k#!divAbstract},
year = {2013},
date = {2013-05-31},
journal = {Soft Matter},
volume = {9},
pages = {8198-8202},
abstract = {Most materials have a unique form optimized for a specific property and function. However, the ability to reconfigure material structures depending on stimuli opens exciting opportunities. Although mechanical instabilities have been traditionally viewed as a failure mode, here we exploit them to design a class of 2D soft materials whose architecture can be dramatically changed in response to an external stimulus. By considering geometric constraints on the tessellations of the 2D Euclidean plane, we have identified four possible periodic distributions of uniform circular holes where mechanical instability can be exploited to reversibly switch between expanded (i.e. with circular holes) and compact (i.e. with elongated, almost closed elliptical holes) periodic configurations. Interestingly, in all these structures buckling is found to induce large negative values of incremental Poisson's ratio and in two of them also the formation of chiral patterns. Using a combination of finite element simulations and experiments at the centimeter scale we demonstrate a proof-of-concept of the proposed materials. Since the proposed mechanism for reconfigurable materials is induced by elastic instability, it is reversible, repeatable and scale-independent.},
note = {Highlighted on the Soft Matter blog.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Most materials have a unique form optimized for a specific property and function. However, the ability to reconfigure material structures depending on stimuli opens exciting opportunities. Although mechanical instabilities have been traditionally viewed as a failure mode, here we exploit them to design a class of 2D soft materials whose architecture can be dramatically changed in response to an external stimulus. By considering geometric constraints on the tessellations of the 2D Euclidean plane, we have identified four possible periodic distributions of uniform circular holes where mechanical instability can be exploited to reversibly switch between expanded (i.e. with circular holes) and compact (i.e. with elongated, almost closed elliptical holes) periodic configurations. Interestingly, in all these structures buckling is found to induce large negative values of incremental Poisson’s ratio and in two of them also the formation of chiral patterns. Using a combination of finite element simulations and experiments at the centimeter scale we demonstrate a proof-of-concept of the proposed materials. Since the proposed mechanism for reconfigurable materials is induced by elastic instability, it is reversible, repeatable and scale-independent.
Note: Send e-mail to Prof. Kang at [email protected] if you need a pdf file of the papers below.
2017
Wang, Pai; Zheng, Yue; Fernandes, Matheus C.; Sun, Yushen; Xu, Kai; Sun, Sijie; Kang, Sung Hoon; Tournat, Vincent; Bertoldi, Katia
Harnessing Geometric Frustration to Form Band Gaps in Acoustic Channel Lattices Journal Article
In: Physical Review Letters, vol. 118, pp. 084302, 2017.
Abstract | Links | BibTeX | Tags: Acoustic, architected materials, Band gap, Geometrical Frustration, Metamaterial
@article{Wang2017,
title = {Harnessing Geometric Frustration to Form Band Gaps in Acoustic Channel Lattices},
author = {Pai Wang and Yue Zheng and Matheus C. Fernandes and Yushen Sun and Kai Xu and Sijie Sun and Sung Hoon Kang and Vincent Tournat and Katia Bertoldi},
url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.084302},
doi = {10.1103/PhysRevLett.118.084302},
year = {2017},
date = {2017-02-21},
journal = {Physical Review Letters},
volume = {118},
pages = {084302},
abstract = {We demonstrate both numerically and experimentally that geometric frustration in two-dimensional periodic acoustic networks consisting of arrays of narrow air channels can be harnessed to form band gaps (ranges of frequency in which the waves cannot propagate in any direction through the system). While resonant standing wave modes and interferences are ubiquitous in all the analyzed network geometries, we show that they give rise to band gaps only in the geometrically frustrated ones (i.e., those comprising of triangles and pentagons). Our results not only reveal a new mechanism based on geometric frustration to suppress the propagation of pressure waves in specific frequency ranges but also open avenues for the design of a new generation of smart systems that control and manipulate sound and vibrations.},
keywords = {Acoustic, architected materials, Band gap, Geometrical Frustration, Metamaterial},
pubstate = {published},
tppubtype = {article}
}
We demonstrate both numerically and experimentally that geometric frustration in two-dimensional periodic acoustic networks consisting of arrays of narrow air channels can be harnessed to form band gaps (ranges of frequency in which the waves cannot propagate in any direction through the system). While resonant standing wave modes and interferences are ubiquitous in all the analyzed network geometries, we show that they give rise to band gaps only in the geometrically frustrated ones (i.e., those comprising of triangles and pentagons). Our results not only reveal a new mechanism based on geometric frustration to suppress the propagation of pressure waves in specific frequency ranges but also open avenues for the design of a new generation of smart systems that control and manipulate sound and vibrations.
2016
Zárate, Yair; Babaee, Sahab; Kang, Sung H.; Neshev, Dragomir N.; Shadrivov, Ilya V.; Bertoldi, Katia; Powell, David A.
Elastic metamaterials for tuning circular polarization of electromagnetic waves Journal Article
In: Scientific Reports, vol. 6, pp. 28273, 2016.
Abstract | Links | BibTeX | Tags: 3D printing, Auxetic, buckling, Chiral, electromagnetic, Metamaterial, Tunable
@article{Zárate2016,
title = {Elastic metamaterials for tuning circular polarization of electromagnetic waves},
author = {Yair Zárate and Sahab Babaee and Sung H. Kang and Dragomir N. Neshev and Ilya V. Shadrivov and Katia Bertoldi and David A. Powell},
url = {http://www.nature.com/articles/srep28273},
doi = {doi:10.1038/srep28273},
year = {2016},
date = {2016-06-20},
journal = {Scientific Reports},
volume = {6},
pages = {28273},
abstract = {Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.},
keywords = {3D printing, Auxetic, buckling, Chiral, electromagnetic, Metamaterial, Tunable},
pubstate = {published},
tppubtype = {article}
}
Electromagnetic resonators are integrated with advanced elastic material to develop a new type of tunable metamaterial. An electromagnetic-elastic metamaterial able to switch on and off its electromagnetic chiral response is experimentally demonstrated. Such tunability is attained by harnessing the unique buckling properties of auxetic elastic materials (buckliballs) with embedded electromagnetic resonators. In these structures, simple uniaxial compression results in a complex but controlled pattern of deformation, resulting in a shift of its electromagnetic resonance, and in the structure transforming to a chiral state. The concept can be extended to the tuning of three-dimensional materials constructed from the meta-molecules, since all the components twist and deform into the same chiral configuration when compressed.
2014
Shan, Sicong; Kang, Sung Hoon; Wang, Pai; Qu, Cangyu; Shian, Samuel; Chen, Elizabeth R.; Weaver, James C.; Bertoldi, Katia
Harnessing Multiple Folding Mechanisms in Soft Periodic and Porous Structures to Design Highly Tunable Phononic Crystals Journal Article
In: Advanced Functional Materials, vol. 24, pp. 4935–4942, 2014.
Abstract | Links | BibTeX | Tags: 3D printing, architected materials, Folding Mechanismsm, mechanics of soft materials and structures, Metamaterial, Phononic Crystals, Soft Periodic Porous Structures, Tunability
@article{Shan2014,
title = {Harnessing Multiple Folding Mechanisms in Soft Periodic and Porous Structures to Design Highly Tunable Phononic Crystals},
author = {Sicong Shan and Sung Hoon Kang and Pai Wang and Cangyu Qu and Samuel Shian and Elizabeth R. Chen and James C. Weaver and Katia Bertoldi},
url = {http://onlinelibrary.wiley.com/doi/10.1002/adfm.201400665/abstract},
year = {2014},
date = {2014-08-20},
journal = {Advanced Functional Materials},
volume = {24},
pages = {4935–4942},
abstract = {Mechanical instabilities in periodic porous elastic structures may lead to the formation of homogeneous patterns, opening avenues for a wide range of applications that are related to the geometry of the system. This study focuses on an elastomeric porous structure comprising a triangular array of circular holes, and shows that by controlling the loading direction, multiple pattern transformations can be induced by buckling. Interestingly, these different pattern transformations can be exploited to design materials with highly tunable properties. In particular, these results indicate that they can be effectively used to tune the propagation of elastic waves in phononic crystals, enhancing the tunability of the dynamic response of the system. Using a combination of finite element simulations and experiments, a proof-of-concept of the novel material is demonstrated. Since the proposed mechanism is induced by elastic instability, it is reversible, repeatable, and scale-independent, opening avenues for the design of highly tunable materials and devices over a wide range of length scales.},
keywords = {3D printing, architected materials, Folding Mechanismsm, mechanics of soft materials and structures, Metamaterial, Phononic Crystals, Soft Periodic Porous Structures, Tunability},
pubstate = {published},
tppubtype = {article}
}
Mechanical instabilities in periodic porous elastic structures may lead to the formation of homogeneous patterns, opening avenues for a wide range of applications that are related to the geometry of the system. This study focuses on an elastomeric porous structure comprising a triangular array of circular holes, and shows that by controlling the loading direction, multiple pattern transformations can be induced by buckling. Interestingly, these different pattern transformations can be exploited to design materials with highly tunable properties. In particular, these results indicate that they can be effectively used to tune the propagation of elastic waves in phononic crystals, enhancing the tunability of the dynamic response of the system. Using a combination of finite element simulations and experiments, a proof-of-concept of the novel material is demonstrated. Since the proposed mechanism is induced by elastic instability, it is reversible, repeatable, and scale-independent, opening avenues for the design of highly tunable materials and devices over a wide range of length scales.
2013
Shim, Jongmin; Shan, Sicong; Kosmrlj, Andrej; Kang, Sung Hoon; Chen, Elizabeth R.; Weaver, James C.; Bertoldi, Katia
Harnessing Instabilities for Design of Soft Reconfigurable Auxetic/Chiral Materials Journal Article
In: Soft Matter, vol. 9, pp. 8198-8202, 2013, (Highlighted on the Soft Matter blog.).
Abstract | Links | BibTeX | Tags: 3D printing, architected materials, Auxetic, Chiral, Mechanical Instability, mechanics of soft materials and structures, Metamaterial, Soft Periodic Porous Structures, Symmetry Breaking
@article{Shim2013,
title = {Harnessing Instabilities for Design of Soft Reconfigurable Auxetic/Chiral Materials},
author = {Jongmin Shim and Sicong Shan and Andrej Kosmrlj and Sung Hoon Kang and Elizabeth R. Chen and James C. Weaver and Katia Bertoldi},
url = {http://pubs.rsc.org/en/content/articlelanding/2013/sm/c3sm51148k#!divAbstract},
year = {2013},
date = {2013-05-31},
journal = {Soft Matter},
volume = {9},
pages = {8198-8202},
abstract = {Most materials have a unique form optimized for a specific property and function. However, the ability to reconfigure material structures depending on stimuli opens exciting opportunities. Although mechanical instabilities have been traditionally viewed as a failure mode, here we exploit them to design a class of 2D soft materials whose architecture can be dramatically changed in response to an external stimulus. By considering geometric constraints on the tessellations of the 2D Euclidean plane, we have identified four possible periodic distributions of uniform circular holes where mechanical instability can be exploited to reversibly switch between expanded (i.e. with circular holes) and compact (i.e. with elongated, almost closed elliptical holes) periodic configurations. Interestingly, in all these structures buckling is found to induce large negative values of incremental Poisson's ratio and in two of them also the formation of chiral patterns. Using a combination of finite element simulations and experiments at the centimeter scale we demonstrate a proof-of-concept of the proposed materials. Since the proposed mechanism for reconfigurable materials is induced by elastic instability, it is reversible, repeatable and scale-independent.},
note = {Highlighted on the Soft Matter blog.},
keywords = {3D printing, architected materials, Auxetic, Chiral, Mechanical Instability, mechanics of soft materials and structures, Metamaterial, Soft Periodic Porous Structures, Symmetry Breaking},
pubstate = {published},
tppubtype = {article}
}
Most materials have a unique form optimized for a specific property and function. However, the ability to reconfigure material structures depending on stimuli opens exciting opportunities. Although mechanical instabilities have been traditionally viewed as a failure mode, here we exploit them to design a class of 2D soft materials whose architecture can be dramatically changed in response to an external stimulus. By considering geometric constraints on the tessellations of the 2D Euclidean plane, we have identified four possible periodic distributions of uniform circular holes where mechanical instability can be exploited to reversibly switch between expanded (i.e. with circular holes) and compact (i.e. with elongated, almost closed elliptical holes) periodic configurations. Interestingly, in all these structures buckling is found to induce large negative values of incremental Poisson’s ratio and in two of them also the formation of chiral patterns. Using a combination of finite element simulations and experiments at the centimeter scale we demonstrate a proof-of-concept of the proposed materials. Since the proposed mechanism for reconfigurable materials is induced by elastic instability, it is reversible, repeatable and scale-independent.