Publications
Shan, Sicong; Kang, Sung H.; Zhao, Zhenhao; Fang, Lichen; Bertoldi, Katia
Design of planar isotropic negative Poisson’s ratio structures Journal Article
In: Extreme Mechanics Letters, vol. 4, pp. 96–102, 2015, ISSN: 2352-4316.
@article{Shan2015,
title = {Design of planar isotropic negative Poisson’s ratio structures},
author = {Sicong Shan and Sung H. Kang and Zhenhao Zhao and Lichen Fang and Katia Bertoldi},
url = {http://www.sciencedirect.com/science/article/pii/S2352431615000759},
doi = {10.1016/j.eml.2015.05.002},
issn = {2352-4316},
year = {2015},
date = {2015-05-21},
journal = {Extreme Mechanics Letters},
volume = {4},
pages = {96–102},
abstract = {Most of the auxetic materials that have been characterized experimentally or studied analytically are anisotropic and this limits their possible applications, as they need to be carefully oriented during operation. Here, through a combined numerical and experimental approach, we demonstrate that 2D auxetic materials with isotropic response can be easily realized by perforating a sheet with elongated cuts arranged to form a periodic pattern with either six-fold or three-fold symmetry. Moreover, we also show that the auxetic behavior can be easily tuned by varying the length of the cuts and that it is retained even under large levels of applied deformation beyond the limit of small strains. This novel, simple and scalable design can serve as an important guideline for designing and fabricating isotropic auxetic materials that can have a significant impact on a wide range of applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Grinthal, Alison; Kang, Sung Hoon; Epstein, Alexander K.; Aizenberg, Michael; Khan, Mughees; Aizenberg, Joanna
Steering Nanofibers: An Integrative Approach to Bio-Inspired Fiber Fabrication and Assembly Journal Article
In: Nano Today, vol. 7, pp. 35-52, 2012, (Invited Review).
@article{Grinthal2012,
title = {Steering Nanofibers: An Integrative Approach to Bio-Inspired Fiber Fabrication and Assembly},
author = {Alison Grinthal and Sung Hoon Kang and Alexander K. Epstein and Michael Aizenberg and Mughees Khan and Joanna Aizenberg},
url = {http://www.sciencedirect.com/science/article/pii/S1748013211001411},
year = {2012},
date = {2012-02-01},
journal = {Nano Today},
volume = {7},
pages = {35-52},
abstract = {As seen throughout the natural world, nanoscale fibers exhibit a unique combination of mechanical and surface properties that enable them to wind and bend around each other into an immense diversity of complex forms. In this review, we discuss how this versatility can be harnessed to transform a simple array of anchored nanofibers into a variety of complex, hierarchically organized dynamic functional surfaces. We describe a set of recently developed benchtop techniques that provide a straightforward way to generate libraries of fibrous surfaces with a wide range of finely tuned, nearly arbitrary geometric, mechanical, material, and surface characteristics starting from a single master array. These simple systematic controls can be used to program the fibers to bundle together, twist around each other into chiral swirls, and assemble into patterned arrays of complex hierarchical architectures. The delicate balance between fiber elasticity and surface adhesion plays a critical role in determining the shape, chirality, and higher order of the assembled structures, as does the dynamic evolution of the geometric, mechanical, and surface parameters throughout the assembly process. Hierarchical assembly can also be programmed to run backwards, enabling a wide range of reversible, responsive behaviors to be encoded through rationally chosen surface chemistry. These strategies provide a foundation for designing a vast assortment of functional surfaces with anti-fouling, adhesive, optical, water and ice repellent, memory storage, microfluidic, capture and release, and many more capabilities with the structural and dynamic sophistication of their biological counterparts.},
note = {Invited Review},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Note: Send e-mail to Prof. Kang at [email protected] if you need a pdf file of the papers below.
2015

Shan, Sicong; Kang, Sung H.; Zhao, Zhenhao; Fang, Lichen; Bertoldi, Katia
Design of planar isotropic negative Poisson’s ratio structures Journal Article
In: Extreme Mechanics Letters, vol. 4, pp. 96–102, 2015, ISSN: 2352-4316.
Abstract | Links | BibTeX | Tags: architected materials, Auxetic, Isotropic, Symmetry
@article{Shan2015,
title = {Design of planar isotropic negative Poisson’s ratio structures},
author = {Sicong Shan and Sung H. Kang and Zhenhao Zhao and Lichen Fang and Katia Bertoldi},
url = {http://www.sciencedirect.com/science/article/pii/S2352431615000759},
doi = {10.1016/j.eml.2015.05.002},
issn = {2352-4316},
year = {2015},
date = {2015-05-21},
journal = {Extreme Mechanics Letters},
volume = {4},
pages = {96–102},
abstract = {Most of the auxetic materials that have been characterized experimentally or studied analytically are anisotropic and this limits their possible applications, as they need to be carefully oriented during operation. Here, through a combined numerical and experimental approach, we demonstrate that 2D auxetic materials with isotropic response can be easily realized by perforating a sheet with elongated cuts arranged to form a periodic pattern with either six-fold or three-fold symmetry. Moreover, we also show that the auxetic behavior can be easily tuned by varying the length of the cuts and that it is retained even under large levels of applied deformation beyond the limit of small strains. This novel, simple and scalable design can serve as an important guideline for designing and fabricating isotropic auxetic materials that can have a significant impact on a wide range of applications.},
keywords = {architected materials, Auxetic, Isotropic, Symmetry},
pubstate = {published},
tppubtype = {article}
}
2012

Grinthal, Alison; Kang, Sung Hoon; Epstein, Alexander K.; Aizenberg, Michael; Khan, Mughees; Aizenberg, Joanna
Steering Nanofibers: An Integrative Approach to Bio-Inspired Fiber Fabrication and Assembly Journal Article
In: Nano Today, vol. 7, pp. 35-52, 2012, (Invited Review).
Abstract | Links | BibTeX | Tags: Assembly, Bio-Inspired, bio-inspired science and engineering, Chemistry, Fabrication, Geometry, Hierarchical, Mechanics, Nanofiber, Symmetry
@article{Grinthal2012,
title = {Steering Nanofibers: An Integrative Approach to Bio-Inspired Fiber Fabrication and Assembly},
author = {Alison Grinthal and Sung Hoon Kang and Alexander K. Epstein and Michael Aizenberg and Mughees Khan and Joanna Aizenberg},
url = {http://www.sciencedirect.com/science/article/pii/S1748013211001411},
year = {2012},
date = {2012-02-01},
journal = {Nano Today},
volume = {7},
pages = {35-52},
abstract = {As seen throughout the natural world, nanoscale fibers exhibit a unique combination of mechanical and surface properties that enable them to wind and bend around each other into an immense diversity of complex forms. In this review, we discuss how this versatility can be harnessed to transform a simple array of anchored nanofibers into a variety of complex, hierarchically organized dynamic functional surfaces. We describe a set of recently developed benchtop techniques that provide a straightforward way to generate libraries of fibrous surfaces with a wide range of finely tuned, nearly arbitrary geometric, mechanical, material, and surface characteristics starting from a single master array. These simple systematic controls can be used to program the fibers to bundle together, twist around each other into chiral swirls, and assemble into patterned arrays of complex hierarchical architectures. The delicate balance between fiber elasticity and surface adhesion plays a critical role in determining the shape, chirality, and higher order of the assembled structures, as does the dynamic evolution of the geometric, mechanical, and surface parameters throughout the assembly process. Hierarchical assembly can also be programmed to run backwards, enabling a wide range of reversible, responsive behaviors to be encoded through rationally chosen surface chemistry. These strategies provide a foundation for designing a vast assortment of functional surfaces with anti-fouling, adhesive, optical, water and ice repellent, memory storage, microfluidic, capture and release, and many more capabilities with the structural and dynamic sophistication of their biological counterparts.},
note = {Invited Review},
keywords = {Assembly, Bio-Inspired, bio-inspired science and engineering, Chemistry, Fabrication, Geometry, Hierarchical, Mechanics, Nanofiber, Symmetry},
pubstate = {published},
tppubtype = {article}
}