Publications
1.
Xun, Helen; Clarke, Scott; Baker, Nusaiba; Shallal, Christopher; Lee, Erica; Fadavi, Darya; Wong, Alison; Brandacher, Gerald; Kang, Sung Hoon; Sacks, Justin M
Method, Material, and Machine: A Review for the Surgeon Using Three-Dimensional Printing for Accelerated Device Production Journal Article
In: Journal of the American College of Surgeons, vol. 232, no. 5, pp. 726–737, 2021.
@article{xun2021method,
title = {Method, Material, and Machine: A Review for the Surgeon Using Three-Dimensional Printing for Accelerated Device Production},
author = {Helen Xun and Scott Clarke and Nusaiba Baker and Christopher Shallal and Erica Lee and Darya Fadavi and Alison Wong and Gerald Brandacher and Sung Hoon Kang and Justin M Sacks},
url = {https://scholar.google.com/citations?view_op=view_citation&hl=en&user=RKlXTzoAAAAJ&sortby=pubdate&citation_for_view=RKlXTzoAAAAJ:ZuybSZzF8UAC#:~:text=Sung%20Hoon%20Kang-,Method%2C%20Material%2C%20and%20Machine%3A%20A%20Review%20for%20the%20Surgeon%20Using%20Three-Dimensional%20Printing%20for%20Accelerated%20Device%20Production,-Authors},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Journal of the American College of Surgeons},
volume = {232},
number = {5},
pages = {726--737},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2.
Fang, Lichen; Yan, Yishu; Agarwal, Ojaswi; Yao, Shengyu; Seppala, Jonathan E.; Kang, Sung Hoon
Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication Journal Article
In: Materials , vol. 13, no. 19, 2020.
@article{Fang2020b,
title = {Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication},
author = {Lichen Fang and Yishu Yan and Ojaswi Agarwal and Shengyu Yao and Jonathan E. Seppala and Sung Hoon Kang
},
url = {https://www.mdpi.com/1996-1944/13/19/4414},
doi = {https://doi.org/10.3390/ma13194414},
year = {2020},
date = {2020-10-03},
journal = {Materials },
volume = {13},
number = {19},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
3.
Fang, Lichen; Yan, Yishu; Agarwal, Ojaswi; Seppala, Jonathan E.; Hemker, Kevin J.; Kang, Sung Hoon
Processing-structure-property relationships of bisphenol-A-polycarbonate samples prepared by fused filament fabrication Journal Article
In: Additive Manufacturing, vol. 35, 2020.
@article{Fang2020,
title = {Processing-structure-property relationships of bisphenol-A-polycarbonate samples prepared by fused filament fabrication},
author = {Lichen Fang and Yishu Yan and Ojaswi Agarwal and Jonathan E. Seppala and Kevin J. Hemker and Sung Hoon Kang},
url = {https://www.sciencedirect.com/science/article/pii/S2214860420306576},
doi = {https://doi.org/10.1016/j.addma.2020.101285},
year = {2020},
date = {2020-05-11},
journal = {Additive Manufacturing},
volume = {35},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
4.
Shen, Beijun; Erol, Ozan; Fang, Lichen; Kang, Sung Hoon
Programming the time into 3D printing: current advances and future directions in 4D printing Journal Article
In: Multifunctional Materials, vol. 3, no. 1, 2020.
@article{Shen2020,
title = {Programming the time into 3D printing: current advances and future directions in 4D printing},
author = {Beijun Shen and Ozan Erol and Lichen Fang and Sung Hoon Kang},
url = {https://iopscience.iop.org/article/10.1088/2399-7532/ab54ea},
doi = {https://doi.org/10.1088/2399-7532/ab54ea},
year = {2020},
date = {2020-01-23},
journal = {Multifunctional Materials},
volume = {3},
number = {1},
abstract = {The recent advances in wearable electronics and intelligent human-machine interface systems have garnered great interests in electromechanical sensors, which can measure and quantify physical stimuli. Among different types of electromechanical sensors, piezoresistive sensors have been extensively investigated due to the excellent sensitivity, simple construction, and durability. Especially, there have been remarkable developments of flexible and stretchable piezoresistive sensors for wearable devices by investigating novel material/structural strategies to obtain highly sensitive piezoresistive sensors with skin-like flexibility. Here, we give a comprehensive overview of the recent progress in flexible and stretchable piezoresistive sensors and their applications. Based on the material composition and structural characteristics, the piezoresistive sensors are categorized into three types—conductive polymeric composite, porous conductive material, and architected conductive material. Subsequently, we have summarized their transduction mechanisms, fabrication processes, sensing performances, and applications. Finally, we have discussed current challenges and future opportunities for piezoresistive sensors.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The recent advances in wearable electronics and intelligent human-machine interface systems have garnered great interests in electromechanical sensors, which can measure and quantify physical stimuli. Among different types of electromechanical sensors, piezoresistive sensors have been extensively investigated due to the excellent sensitivity, simple construction, and durability. Especially, there have been remarkable developments of flexible and stretchable piezoresistive sensors for wearable devices by investigating novel material/structural strategies to obtain highly sensitive piezoresistive sensors with skin-like flexibility. Here, we give a comprehensive overview of the recent progress in flexible and stretchable piezoresistive sensors and their applications. Based on the material composition and structural characteristics, the piezoresistive sensors are categorized into three types—conductive polymeric composite, porous conductive material, and architected conductive material. Subsequently, we have summarized their transduction mechanisms, fabrication processes, sensing performances, and applications. Finally, we have discussed current challenges and future opportunities for piezoresistive sensors.
5.
Bachtiar, E. O.; Erol, O.; M. Millrod,; Tao, R.; Gracias, D. H.; Romer, L. H.; Kang, S. H.
3D printing and characterizations of a soft and biostable elastomer with high flexibility and strength for biomedical applications Journal Article
In: Journal of the Mechanical Behavior of Biomedical Materials, 2020.
@article{Bachtiar2020,
title = {3D printing and characterizations of a soft and biostable elastomer with high flexibility and strength for biomedical applications},
author = {E. O. Bachtiar and O. Erol and M. Millrod, and R. Tao and D. H. Gracias and L. H. Romer and S. H. Kang},
url = {https://www.sciencedirect.com/science/article/pii/S1751616119316728},
doi = {https://doi.org/10.1016/j.jmbbm.2020.103649},
year = {2020},
date = {2020-01-23},
journal = {Journal of the Mechanical Behavior of Biomedical Materials},
abstract = {Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via micro-CT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young's modulus of 6.9 ± 0.85 MPa and a failure strain of 457 ± 37.7% while exhibiting good cell viability. Finally, compliant and free-standing structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not just for PCU-Sil but for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via micro-CT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young’s modulus of 6.9 ± 0.85 MPa and a failure strain of 457 ± 37.7% while exhibiting good cell viability. Finally, compliant and free-standing structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not just for PCU-Sil but for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters.
6.
Jeon, S. -Y.; Kang, S. H.
Electrochemical reactions drive morphing of materials Journal Article
In: Nature, vol. 573, pp. 198-199, 2019.
@article{Jeon2019,
title = {Electrochemical reactions drive morphing of materials},
author = {S.-Y. Jeon and S. H. Kang},
url = {https://www.nature.com/articles/d41586-019-02663-9},
doi = {10.1038/d41586-019-02663-9},
year = {2019},
date = {2019-09-11},
journal = {Nature},
volume = {573},
pages = {198-199},
abstract = {Silicon anodes in lithium batteries expand during discharge, causing failure. This expansion has been used constructively in a material whose architecture controllably and reversibly changes to alter its function.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Silicon anodes in lithium batteries expand during discharge, causing failure. This expansion has been used constructively in a material whose architecture controllably and reversibly changes to alter its function.
7.
Jung, Wei-Hung; Elawad, Khalid; Kang, Sung Hoon; Chen, Yun
Cell–Cell Adhesion and Myosin Activity Regulate Cortical Actin Assembly in Mammary Gland Epithelium on Concaved Surface Journal Article
In: Cells, vol. 8, no. 8, pp. 813, 2019.
@article{Jung2019,
title = {Cell–Cell Adhesion and Myosin Activity Regulate Cortical Actin Assembly in Mammary Gland Epithelium on Concaved Surface},
author = {Wei-Hung Jung and Khalid Elawad and Sung Hoon Kang and Yun Chen},
url = {https://www.mdpi.com/2073-4409/8/8/813},
doi = {10.3390/cells8080813},
year = {2019},
date = {2019-08-02},
journal = {Cells},
volume = {8},
number = {8},
pages = {813},
abstract = {It has been demonstrated that geometry can affect cell behaviors. Though curvature-sensitive proteins at the nanoscale are studied, it is unclear how cells sense curvature at the cellular and multicellular levels. To characterize and determine the mechanisms of curvature-dependent cell behaviors, we grow cells on open channels of the 60-µm radius. We found that cortical F-actin is 1.2-fold more enriched in epithelial cells grown on the curved surface compared to the flat control. We observed that myosin activity is required to promote cortical F-actin formation. Furthermore, cell-cell contact was shown to be indispensable for curvature-dependent cortical actin assembly. Our results indicate that the actomyosin network coupled with adherens junctions is involved in curvature-sensing at the multi-cellular level.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
It has been demonstrated that geometry can affect cell behaviors. Though curvature-sensitive proteins at the nanoscale are studied, it is unclear how cells sense curvature at the cellular and multicellular levels. To characterize and determine the mechanisms of curvature-dependent cell behaviors, we grow cells on open channels of the 60-µm radius. We found that cortical F-actin is 1.2-fold more enriched in epithelial cells grown on the curved surface compared to the flat control. We observed that myosin activity is required to promote cortical F-actin formation. Furthermore, cell-cell contact was shown to be indispensable for curvature-dependent cortical actin assembly. Our results indicate that the actomyosin network coupled with adherens junctions is involved in curvature-sensing at the multi-cellular level.
8.
Jiang, Zhuoran; Erol, Ozn; Chatterjee, Devina; Xu, Weinan; Hibino, Narutoshi; Romer, Lewis H.; Kang, Sung Hoon; Gracias, David H.
Direct Ink Writing of Poly(tetrafluoroethylene) (PTFE) with Tunable Mechanical Properties Journal Article
In: ACS Applied Materials and Interfaces, 2019.
@article{Jiang2019,
title = {Direct Ink Writing of Poly(tetrafluoroethylene) (PTFE) with Tunable Mechanical Properties},
author = {Zhuoran Jiang and Ozn Erol and Devina Chatterjee and Weinan Xu and Narutoshi Hibino and Lewis H. Romer and Sung Hoon Kang and David H. Gracias},
url = {https://doi.org/10.1021/acsami.9b07279},
doi = {10.1021/acsami.9b07279},
year = {2019},
date = {2019-07-10},
journal = {ACS Applied Materials and Interfaces},
abstract = {Poly(tetrafluoroethylene) (PTFE) is a unique polymer with highly desirable properties such as resistance to chemical degradation, biocompatibility, hydrophobicity, antistiction, and low friction coefficient. However, due to its high melt viscosity, it is not possible to three-dimensional (3D)-print PTFE structures using nozzle-based extrusion. Here, we report a new and versatile strategy for 3D-printing PTFE structures using direct ink writing (DIW). Our approach is based on a newly formulated PTFE nanoparticle ink and thermal treatment process. The ink was formulated by mixing an aqueous dispersion of surfactant-stabilized PTFE nanoparticles with a binding gum to optimize its shear-thinning properties required for DIW. We developed a multistage thermal treatment to fuse the PTFE nanoparticles, solidify the printed structures, and remove the additives. We have extensively characterized the rheological and mechanical properties and processing parameters of these structures using imaging, mechanical testing, and statistical design of experiments. Importantly, several of the mechanical and structural properties of the final-printed PTFE structures resemble that of compression-molded PTFE, and additionally, the mechanical properties are tunable. We anticipate that this versatile approach facilitates the production of 3D-printed PTFE components using DIW with significant potential applications in engineering and medicine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Poly(tetrafluoroethylene) (PTFE) is a unique polymer with highly desirable properties such as resistance to chemical degradation, biocompatibility, hydrophobicity, antistiction, and low friction coefficient. However, due to its high melt viscosity, it is not possible to three-dimensional (3D)-print PTFE structures using nozzle-based extrusion. Here, we report a new and versatile strategy for 3D-printing PTFE structures using direct ink writing (DIW). Our approach is based on a newly formulated PTFE nanoparticle ink and thermal treatment process. The ink was formulated by mixing an aqueous dispersion of surfactant-stabilized PTFE nanoparticles with a binding gum to optimize its shear-thinning properties required for DIW. We developed a multistage thermal treatment to fuse the PTFE nanoparticles, solidify the printed structures, and remove the additives. We have extensively characterized the rheological and mechanical properties and processing parameters of these structures using imaging, mechanical testing, and statistical design of experiments. Importantly, several of the mechanical and structural properties of the final-printed PTFE structures resemble that of compression-molded PTFE, and additionally, the mechanical properties are tunable. We anticipate that this versatile approach facilitates the production of 3D-printed PTFE components using DIW with significant potential applications in engineering and medicine.
9.
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.
10.
Shan, Sicong; Kang, Sung H.; Raney, Jordan R.; Wang, Pai; Fang, Lichen; Candido, Francisco; Lewis, Jennifer A.; Bertoldi, Katia
Multistable Architected Materials for Trapping Elastic Strain Energy Journal Article
In: Advanced Materials, vol. 27, pp. 4296–4301, 2015, ISSN: 1521-4095, (SS, SHK, JRR: equal contribution).
@article{ADMA:ADMA201501708,
title = {Multistable Architected Materials for Trapping Elastic Strain Energy},
author = {Sicong Shan and Sung H. Kang and Jordan R. Raney and Pai Wang and Lichen Fang and Francisco Candido and Jennifer A. Lewis and Katia Bertoldi},
url = {http://dx.doi.org/10.1002/adma.201501708},
issn = {1521-4095},
year = {2015},
date = {2015-06-18},
journal = {Advanced Materials},
volume = {27},
pages = {4296–4301},
note = {SS, SHK, JRR: equal contribution},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
11.
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.
12.
Kang, Sung Hoon; Bertoldi, Katia; Shan, Sicong
Shape Recoverable Reusable Energy Absorbing Structures, Systems and Methods for Manufacture Thereof Technical Report
2014, (United States Provisional Patent Application No. 61/983,782).
@techreport{Kang2014b,
title = {Shape Recoverable Reusable Energy Absorbing Structures, Systems and Methods for Manufacture Thereof},
author = {Sung Hoon Kang and Katia Bertoldi and Sicong Shan},
year = {2014},
date = {2014-04-24},
booktitle = {U.S. Provisional Patent Application No. 61/983,782},
note = {United States Provisional Patent Application No. 61/983,782},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
13.
Kang, Sung Hoon; Shan, Sicong; Košmrlj, Andrej; Noorduin, Wim L.; Shian, Samuel; Weaver, James C.; Clarke, David R.; Bertoldi, Katia
Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular Structures Journal Article
In: Physical Review Letters, vol. 112, pp. 098701, 2014, (Selected as Physical Review Letters Editors’ Suggestion and Highlighted in Physics Synopsis.).
@article{Kang2014,
title = {Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular Structures},
author = {Sung Hoon Kang and Sicong Shan and Andrej Košmrlj and Wim L. Noorduin and Samuel Shian and James C. Weaver and David R. Clarke and Katia Bertoldi},
url = {http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.098701},
year = {2014},
date = {2014-03-05},
journal = {Physical Review Letters},
volume = {112},
pages = {098701},
abstract = {Geometrical frustration arises when a local order cannot propagate throughout the space because of geometrical constraints. This phenomenon plays a major role in many systems leading to disordered ground-state configurations. Here, we report a theoretical and experimental study on the behavior of buckling-induced geometrically frustrated triangular cellular structures. To our surprise, we find that buckling induces complex ordered patterns which can be tuned by controlling the porosity of the structures. Our analysis reveals that the connected geometry of the cellular structure plays a crucial role in the generation of ordered states in this frustrated system.},
note = {Selected as Physical Review Letters Editors’ Suggestion and Highlighted in Physics Synopsis.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Geometrical frustration arises when a local order cannot propagate throughout the space because of geometrical constraints. This phenomenon plays a major role in many systems leading to disordered ground-state configurations. Here, we report a theoretical and experimental study on the behavior of buckling-induced geometrically frustrated triangular cellular structures. To our surprise, we find that buckling induces complex ordered patterns which can be tuned by controlling the porosity of the structures. Our analysis reveals that the connected geometry of the cellular structure plays a crucial role in the generation of ordered states in this frustrated system.
14.
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.
15.
Kang, Sung Hoon; Shan, Sicong; Noorduin, Wim L.; Khan, Mughees; Aizenberg, Joanna; Bertoldi, Katia
Buckling-Induced Reversible Symmetry Breaking and Chiral Amplification Using Supported Cellular Structures Journal Article
In: Advanced Materials, vol. 25, pp. 3380-3385, 2013, (SHK, SS, and WLN contributed equally. Highlighted in the June 2013 issue of Nature Physics).
@article{Kang2013,
title = {Buckling-Induced Reversible Symmetry Breaking and Chiral Amplification Using Supported Cellular Structures},
author = {Sung Hoon Kang and Sicong Shan and Wim L. Noorduin and Mughees Khan and Joanna Aizenberg and Katia Bertoldi},
url = {http://onlinelibrary.wiley.com/doi/10.1002/adma.201300617/abstract},
year = {2013},
date = {2013-05-02},
journal = {Advanced Materials},
volume = {25},
pages = {3380-3385},
abstract = {Buckling-induced reversible symmetry breaking and amplification of chirality using macro- and microscale supported cellular structures is described. Guided by extensive theoretical analysis, cellular structures are rationally designed, in which buckling induces a reversible switching between achiral and chiral configurations. Additionally, it is demonstrated that the proposed mechanism can be generalized over a wide range of length scales, geometries, materials, and stimuli. },
note = {SHK, SS, and WLN contributed equally.
Highlighted in the June 2013 issue of Nature Physics},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Buckling-induced reversible symmetry breaking and amplification of chirality using macro- and microscale supported cellular structures is described. Guided by extensive theoretical analysis, cellular structures are rationally designed, in which buckling induces a reversible switching between achiral and chiral configurations. Additionally, it is demonstrated that the proposed mechanism can be generalized over a wide range of length scales, geometries, materials, and stimuli.
Note: Send e-mail to Prof. Kang at [email protected] if you need a pdf file of the papers below.
2021
Xun, Helen; Clarke, Scott; Baker, Nusaiba; Shallal, Christopher; Lee, Erica; Fadavi, Darya; Wong, Alison; Brandacher, Gerald; Kang, Sung Hoon; Sacks, Justin M
Method, Material, and Machine: A Review for the Surgeon Using Three-Dimensional Printing for Accelerated Device Production Journal Article
In: Journal of the American College of Surgeons, vol. 232, no. 5, pp. 726–737, 2021.
Links | BibTeX | Tags: 3D printing
@article{xun2021method,
title = {Method, Material, and Machine: A Review for the Surgeon Using Three-Dimensional Printing for Accelerated Device Production},
author = {Helen Xun and Scott Clarke and Nusaiba Baker and Christopher Shallal and Erica Lee and Darya Fadavi and Alison Wong and Gerald Brandacher and Sung Hoon Kang and Justin M Sacks},
url = {https://scholar.google.com/citations?view_op=view_citation&hl=en&user=RKlXTzoAAAAJ&sortby=pubdate&citation_for_view=RKlXTzoAAAAJ:ZuybSZzF8UAC#:~:text=Sung%20Hoon%20Kang-,Method%2C%20Material%2C%20and%20Machine%3A%20A%20Review%20for%20the%20Surgeon%20Using%20Three-Dimensional%20Printing%20for%20Accelerated%20Device%20Production,-Authors},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Journal of the American College of Surgeons},
volume = {232},
number = {5},
pages = {726--737},
publisher = {Elsevier},
keywords = {3D printing},
pubstate = {published},
tppubtype = {article}
}
2020
Fang, Lichen; Yan, Yishu; Agarwal, Ojaswi; Yao, Shengyu; Seppala, Jonathan E.; Kang, Sung Hoon
Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication Journal Article
In: Materials , vol. 13, no. 19, 2020.
Links | BibTeX | Tags: 3D printing, humidity, mechanical properties, modulus, temperature, toughness
@article{Fang2020b,
title = {Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication},
author = {Lichen Fang and Yishu Yan and Ojaswi Agarwal and Shengyu Yao and Jonathan E. Seppala and Sung Hoon Kang
},
url = {https://www.mdpi.com/1996-1944/13/19/4414},
doi = {https://doi.org/10.3390/ma13194414},
year = {2020},
date = {2020-10-03},
journal = {Materials },
volume = {13},
number = {19},
keywords = {3D printing, humidity, mechanical properties, modulus, temperature, toughness},
pubstate = {published},
tppubtype = {article}
}
Fang, Lichen; Yan, Yishu; Agarwal, Ojaswi; Seppala, Jonathan E.; Hemker, Kevin J.; Kang, Sung Hoon
Processing-structure-property relationships of bisphenol-A-polycarbonate samples prepared by fused filament fabrication Journal Article
In: Additive Manufacturing, vol. 35, 2020.
Links | BibTeX | Tags: 3D printing, Geometry, mechancal properties, modulus, toughness
@article{Fang2020,
title = {Processing-structure-property relationships of bisphenol-A-polycarbonate samples prepared by fused filament fabrication},
author = {Lichen Fang and Yishu Yan and Ojaswi Agarwal and Jonathan E. Seppala and Kevin J. Hemker and Sung Hoon Kang},
url = {https://www.sciencedirect.com/science/article/pii/S2214860420306576},
doi = {https://doi.org/10.1016/j.addma.2020.101285},
year = {2020},
date = {2020-05-11},
journal = {Additive Manufacturing},
volume = {35},
keywords = {3D printing, Geometry, mechancal properties, modulus, toughness},
pubstate = {published},
tppubtype = {article}
}
Shen, Beijun; Erol, Ozan; Fang, Lichen; Kang, Sung Hoon
Programming the time into 3D printing: current advances and future directions in 4D printing Journal Article
In: Multifunctional Materials, vol. 3, no. 1, 2020.
Abstract | Links | BibTeX | Tags: 3D printing
@article{Shen2020,
title = {Programming the time into 3D printing: current advances and future directions in 4D printing},
author = {Beijun Shen and Ozan Erol and Lichen Fang and Sung Hoon Kang},
url = {https://iopscience.iop.org/article/10.1088/2399-7532/ab54ea},
doi = {https://doi.org/10.1088/2399-7532/ab54ea},
year = {2020},
date = {2020-01-23},
journal = {Multifunctional Materials},
volume = {3},
number = {1},
abstract = {The recent advances in wearable electronics and intelligent human-machine interface systems have garnered great interests in electromechanical sensors, which can measure and quantify physical stimuli. Among different types of electromechanical sensors, piezoresistive sensors have been extensively investigated due to the excellent sensitivity, simple construction, and durability. Especially, there have been remarkable developments of flexible and stretchable piezoresistive sensors for wearable devices by investigating novel material/structural strategies to obtain highly sensitive piezoresistive sensors with skin-like flexibility. Here, we give a comprehensive overview of the recent progress in flexible and stretchable piezoresistive sensors and their applications. Based on the material composition and structural characteristics, the piezoresistive sensors are categorized into three types—conductive polymeric composite, porous conductive material, and architected conductive material. Subsequently, we have summarized their transduction mechanisms, fabrication processes, sensing performances, and applications. Finally, we have discussed current challenges and future opportunities for piezoresistive sensors.},
keywords = {3D printing},
pubstate = {published},
tppubtype = {article}
}
The recent advances in wearable electronics and intelligent human-machine interface systems have garnered great interests in electromechanical sensors, which can measure and quantify physical stimuli. Among different types of electromechanical sensors, piezoresistive sensors have been extensively investigated due to the excellent sensitivity, simple construction, and durability. Especially, there have been remarkable developments of flexible and stretchable piezoresistive sensors for wearable devices by investigating novel material/structural strategies to obtain highly sensitive piezoresistive sensors with skin-like flexibility. Here, we give a comprehensive overview of the recent progress in flexible and stretchable piezoresistive sensors and their applications. Based on the material composition and structural characteristics, the piezoresistive sensors are categorized into three types—conductive polymeric composite, porous conductive material, and architected conductive material. Subsequently, we have summarized their transduction mechanisms, fabrication processes, sensing performances, and applications. Finally, we have discussed current challenges and future opportunities for piezoresistive sensors.
Bachtiar, E. O.; Erol, O.; M. Millrod,; Tao, R.; Gracias, D. H.; Romer, L. H.; Kang, S. H.
3D printing and characterizations of a soft and biostable elastomer with high flexibility and strength for biomedical applications Journal Article
In: Journal of the Mechanical Behavior of Biomedical Materials, 2020.
Abstract | Links | BibTeX | Tags: 3D printing
@article{Bachtiar2020,
title = {3D printing and characterizations of a soft and biostable elastomer with high flexibility and strength for biomedical applications},
author = {E. O. Bachtiar and O. Erol and M. Millrod, and R. Tao and D. H. Gracias and L. H. Romer and S. H. Kang},
url = {https://www.sciencedirect.com/science/article/pii/S1751616119316728},
doi = {https://doi.org/10.1016/j.jmbbm.2020.103649},
year = {2020},
date = {2020-01-23},
journal = {Journal of the Mechanical Behavior of Biomedical Materials},
abstract = {Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via micro-CT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young's modulus of 6.9 ± 0.85 MPa and a failure strain of 457 ± 37.7% while exhibiting good cell viability. Finally, compliant and free-standing structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not just for PCU-Sil but for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters.},
keywords = {3D printing},
pubstate = {published},
tppubtype = {article}
}
Recent advancements in 3D printing have revolutionized biomedical engineering by enabling the manufacture of complex and functional devices in a low-cost, customizable, and small-batch fabrication manner. Soft elastomers are particularly important for biomedical applications because they can provide similar mechanical properties as tissues with improved biocompatibility. However, there are very few biocompatible elastomers with 3D printability, and little is known about material properties of biocompatible 3D printable elastomers. Here, we report a new framework to 3D print a soft, biocompatible, and biostable polycarbonate-based urethane silicone (PCU-Sil) with minimal defects. We systematically characterize the rheological and thermal properties of the material to guide the 3D printing process and have determined a range of processing conditions. Optimal printing parameters such as printing speed, temperature, and layer height are determined via parametric studies aimed at minimizing porosity while maximizing the geometric accuracy of the 3D-printed samples as evaluated via micro-CT. We also characterize the mechanical properties of the 3D-printed structures under quasistatic and cyclic loading, degradation behavior and biocompatibility. The 3D-printed materials show a Young’s modulus of 6.9 ± 0.85 MPa and a failure strain of 457 ± 37.7% while exhibiting good cell viability. Finally, compliant and free-standing structures including a patient-specific heart model and a bifurcating arterial structure are printed to demonstrate the versatility of the 3D-printed material. We anticipate that the 3D printing framework presented in this work will open up new possibilities not just for PCU-Sil but for other soft, biocompatible and thermoplastic polymers in various biomedical applications requiring high flexibility and strength combined with biocompatibility, such as vascular implants, heart valves, and catheters.
2019
Jeon, S. -Y.; Kang, S. H.
Electrochemical reactions drive morphing of materials Journal Article
In: Nature, vol. 573, pp. 198-199, 2019.
Abstract | Links | BibTeX | Tags: 3D printing, architected materials, shape, Tunable
@article{Jeon2019,
title = {Electrochemical reactions drive morphing of materials},
author = {S.-Y. Jeon and S. H. Kang},
url = {https://www.nature.com/articles/d41586-019-02663-9},
doi = {10.1038/d41586-019-02663-9},
year = {2019},
date = {2019-09-11},
journal = {Nature},
volume = {573},
pages = {198-199},
abstract = {Silicon anodes in lithium batteries expand during discharge, causing failure. This expansion has been used constructively in a material whose architecture controllably and reversibly changes to alter its function.},
keywords = {3D printing, architected materials, shape, Tunable},
pubstate = {published},
tppubtype = {article}
}
Silicon anodes in lithium batteries expand during discharge, causing failure. This expansion has been used constructively in a material whose architecture controllably and reversibly changes to alter its function.
Jung, Wei-Hung; Elawad, Khalid; Kang, Sung Hoon; Chen, Yun
Cell–Cell Adhesion and Myosin Activity Regulate Cortical Actin Assembly in Mammary Gland Epithelium on Concaved Surface Journal Article
In: Cells, vol. 8, no. 8, pp. 813, 2019.
Abstract | Links | BibTeX | Tags: 3D printing, cell behaviors, curvature sensing, Geometry, multi-cellular
@article{Jung2019,
title = {Cell–Cell Adhesion and Myosin Activity Regulate Cortical Actin Assembly in Mammary Gland Epithelium on Concaved Surface},
author = {Wei-Hung Jung and Khalid Elawad and Sung Hoon Kang and Yun Chen},
url = {https://www.mdpi.com/2073-4409/8/8/813},
doi = {10.3390/cells8080813},
year = {2019},
date = {2019-08-02},
journal = {Cells},
volume = {8},
number = {8},
pages = {813},
abstract = {It has been demonstrated that geometry can affect cell behaviors. Though curvature-sensitive proteins at the nanoscale are studied, it is unclear how cells sense curvature at the cellular and multicellular levels. To characterize and determine the mechanisms of curvature-dependent cell behaviors, we grow cells on open channels of the 60-µm radius. We found that cortical F-actin is 1.2-fold more enriched in epithelial cells grown on the curved surface compared to the flat control. We observed that myosin activity is required to promote cortical F-actin formation. Furthermore, cell-cell contact was shown to be indispensable for curvature-dependent cortical actin assembly. Our results indicate that the actomyosin network coupled with adherens junctions is involved in curvature-sensing at the multi-cellular level.},
keywords = {3D printing, cell behaviors, curvature sensing, Geometry, multi-cellular},
pubstate = {published},
tppubtype = {article}
}
It has been demonstrated that geometry can affect cell behaviors. Though curvature-sensitive proteins at the nanoscale are studied, it is unclear how cells sense curvature at the cellular and multicellular levels. To characterize and determine the mechanisms of curvature-dependent cell behaviors, we grow cells on open channels of the 60-µm radius. We found that cortical F-actin is 1.2-fold more enriched in epithelial cells grown on the curved surface compared to the flat control. We observed that myosin activity is required to promote cortical F-actin formation. Furthermore, cell-cell contact was shown to be indispensable for curvature-dependent cortical actin assembly. Our results indicate that the actomyosin network coupled with adherens junctions is involved in curvature-sensing at the multi-cellular level.
Jiang, Zhuoran; Erol, Ozn; Chatterjee, Devina; Xu, Weinan; Hibino, Narutoshi; Romer, Lewis H.; Kang, Sung Hoon; Gracias, David H.
Direct Ink Writing of Poly(tetrafluoroethylene) (PTFE) with Tunable Mechanical Properties Journal Article
In: ACS Applied Materials and Interfaces, 2019.
Abstract | Links | BibTeX | Tags: 3D printing, additive manufacturing, composites, fluoropolymer, PTFE, Teflon, Tunable
@article{Jiang2019,
title = {Direct Ink Writing of Poly(tetrafluoroethylene) (PTFE) with Tunable Mechanical Properties},
author = {Zhuoran Jiang and Ozn Erol and Devina Chatterjee and Weinan Xu and Narutoshi Hibino and Lewis H. Romer and Sung Hoon Kang and David H. Gracias},
url = {https://doi.org/10.1021/acsami.9b07279},
doi = {10.1021/acsami.9b07279},
year = {2019},
date = {2019-07-10},
journal = {ACS Applied Materials and Interfaces},
abstract = {Poly(tetrafluoroethylene) (PTFE) is a unique polymer with highly desirable properties such as resistance to chemical degradation, biocompatibility, hydrophobicity, antistiction, and low friction coefficient. However, due to its high melt viscosity, it is not possible to three-dimensional (3D)-print PTFE structures using nozzle-based extrusion. Here, we report a new and versatile strategy for 3D-printing PTFE structures using direct ink writing (DIW). Our approach is based on a newly formulated PTFE nanoparticle ink and thermal treatment process. The ink was formulated by mixing an aqueous dispersion of surfactant-stabilized PTFE nanoparticles with a binding gum to optimize its shear-thinning properties required for DIW. We developed a multistage thermal treatment to fuse the PTFE nanoparticles, solidify the printed structures, and remove the additives. We have extensively characterized the rheological and mechanical properties and processing parameters of these structures using imaging, mechanical testing, and statistical design of experiments. Importantly, several of the mechanical and structural properties of the final-printed PTFE structures resemble that of compression-molded PTFE, and additionally, the mechanical properties are tunable. We anticipate that this versatile approach facilitates the production of 3D-printed PTFE components using DIW with significant potential applications in engineering and medicine.},
keywords = {3D printing, additive manufacturing, composites, fluoropolymer, PTFE, Teflon, Tunable},
pubstate = {published},
tppubtype = {article}
}
Poly(tetrafluoroethylene) (PTFE) is a unique polymer with highly desirable properties such as resistance to chemical degradation, biocompatibility, hydrophobicity, antistiction, and low friction coefficient. However, due to its high melt viscosity, it is not possible to three-dimensional (3D)-print PTFE structures using nozzle-based extrusion. Here, we report a new and versatile strategy for 3D-printing PTFE structures using direct ink writing (DIW). Our approach is based on a newly formulated PTFE nanoparticle ink and thermal treatment process. The ink was formulated by mixing an aqueous dispersion of surfactant-stabilized PTFE nanoparticles with a binding gum to optimize its shear-thinning properties required for DIW. We developed a multistage thermal treatment to fuse the PTFE nanoparticles, solidify the printed structures, and remove the additives. We have extensively characterized the rheological and mechanical properties and processing parameters of these structures using imaging, mechanical testing, and statistical design of experiments. Importantly, several of the mechanical and structural properties of the final-printed PTFE structures resemble that of compression-molded PTFE, and additionally, the mechanical properties are tunable. We anticipate that this versatile approach facilitates the production of 3D-printed PTFE components using DIW with significant potential applications in engineering and medicine.
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.
2015
Shan, Sicong; Kang, Sung H.; Raney, Jordan R.; Wang, Pai; Fang, Lichen; Candido, Francisco; Lewis, Jennifer A.; Bertoldi, Katia
Multistable Architected Materials for Trapping Elastic Strain Energy Journal Article
In: Advanced Materials, vol. 27, pp. 4296–4301, 2015, ISSN: 1521-4095, (SS, SHK, JRR: equal contribution).
Links | BibTeX | Tags: 3D printing, architected materials, energy trapping, mechanics of soft materials and structures, multistability, reversibility
@article{ADMA:ADMA201501708,
title = {Multistable Architected Materials for Trapping Elastic Strain Energy},
author = {Sicong Shan and Sung H. Kang and Jordan R. Raney and Pai Wang and Lichen Fang and Francisco Candido and Jennifer A. Lewis and Katia Bertoldi},
url = {http://dx.doi.org/10.1002/adma.201501708},
issn = {1521-4095},
year = {2015},
date = {2015-06-18},
journal = {Advanced Materials},
volume = {27},
pages = {4296–4301},
note = {SS, SHK, JRR: equal contribution},
keywords = {3D printing, architected materials, energy trapping, mechanics of soft materials and structures, multistability, reversibility},
pubstate = {published},
tppubtype = {article}
}
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.
Kang, Sung Hoon; Bertoldi, Katia; Shan, Sicong
Shape Recoverable Reusable Energy Absorbing Structures, Systems and Methods for Manufacture Thereof Technical Report
2014, (United States Provisional Patent Application No. 61/983,782).
BibTeX | Tags: 3D printing, architected materials, Energy-Absorption, Materials, Reversible, Structures
@techreport{Kang2014b,
title = {Shape Recoverable Reusable Energy Absorbing Structures, Systems and Methods for Manufacture Thereof},
author = {Sung Hoon Kang and Katia Bertoldi and Sicong Shan},
year = {2014},
date = {2014-04-24},
booktitle = {U.S. Provisional Patent Application No. 61/983,782},
note = {United States Provisional Patent Application No. 61/983,782},
keywords = {3D printing, architected materials, Energy-Absorption, Materials, Reversible, Structures},
pubstate = {published},
tppubtype = {techreport}
}
Kang, Sung Hoon; Shan, Sicong; Košmrlj, Andrej; Noorduin, Wim L.; Shian, Samuel; Weaver, James C.; Clarke, David R.; Bertoldi, Katia
Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular Structures Journal Article
In: Physical Review Letters, vol. 112, pp. 098701, 2014, (Selected as Physical Review Letters Editors’ Suggestion and Highlighted in Physics Synopsis.).
Abstract | Links | BibTeX | Tags: 3D printing, Cellular Structures, Geometrical Frustration, Mechanical Instability, mechanics of soft materials and structures, Triangular Lattice
@article{Kang2014,
title = {Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular Structures},
author = {Sung Hoon Kang and Sicong Shan and Andrej Košmrlj and Wim L. Noorduin and Samuel Shian and James C. Weaver and David R. Clarke and Katia Bertoldi},
url = {http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.098701},
year = {2014},
date = {2014-03-05},
journal = {Physical Review Letters},
volume = {112},
pages = {098701},
abstract = {Geometrical frustration arises when a local order cannot propagate throughout the space because of geometrical constraints. This phenomenon plays a major role in many systems leading to disordered ground-state configurations. Here, we report a theoretical and experimental study on the behavior of buckling-induced geometrically frustrated triangular cellular structures. To our surprise, we find that buckling induces complex ordered patterns which can be tuned by controlling the porosity of the structures. Our analysis reveals that the connected geometry of the cellular structure plays a crucial role in the generation of ordered states in this frustrated system.},
note = {Selected as Physical Review Letters Editors’ Suggestion and Highlighted in Physics Synopsis.},
keywords = {3D printing, Cellular Structures, Geometrical Frustration, Mechanical Instability, mechanics of soft materials and structures, Triangular Lattice},
pubstate = {published},
tppubtype = {article}
}
Geometrical frustration arises when a local order cannot propagate throughout the space because of geometrical constraints. This phenomenon plays a major role in many systems leading to disordered ground-state configurations. Here, we report a theoretical and experimental study on the behavior of buckling-induced geometrically frustrated triangular cellular structures. To our surprise, we find that buckling induces complex ordered patterns which can be tuned by controlling the porosity of the structures. Our analysis reveals that the connected geometry of the cellular structure plays a crucial role in the generation of ordered states in this frustrated system.
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.
Kang, Sung Hoon; Shan, Sicong; Noorduin, Wim L.; Khan, Mughees; Aizenberg, Joanna; Bertoldi, Katia
Buckling-Induced Reversible Symmetry Breaking and Chiral Amplification Using Supported Cellular Structures Journal Article
In: Advanced Materials, vol. 25, pp. 3380-3385, 2013, (SHK, SS, and WLN contributed equally. Highlighted in the June 2013 issue of Nature Physics).
Abstract | Links | BibTeX | Tags: 3D printing, Amplification, Cellular Structures, Mechanical Instability, mechanics of soft materials and structures, Reversible, Symmetry Breaking
@article{Kang2013,
title = {Buckling-Induced Reversible Symmetry Breaking and Chiral Amplification Using Supported Cellular Structures},
author = {Sung Hoon Kang and Sicong Shan and Wim L. Noorduin and Mughees Khan and Joanna Aizenberg and Katia Bertoldi},
url = {http://onlinelibrary.wiley.com/doi/10.1002/adma.201300617/abstract},
year = {2013},
date = {2013-05-02},
journal = {Advanced Materials},
volume = {25},
pages = {3380-3385},
abstract = {Buckling-induced reversible symmetry breaking and amplification of chirality using macro- and microscale supported cellular structures is described. Guided by extensive theoretical analysis, cellular structures are rationally designed, in which buckling induces a reversible switching between achiral and chiral configurations. Additionally, it is demonstrated that the proposed mechanism can be generalized over a wide range of length scales, geometries, materials, and stimuli. },
note = {SHK, SS, and WLN contributed equally.
Highlighted in the June 2013 issue of Nature Physics},
keywords = {3D printing, Amplification, Cellular Structures, Mechanical Instability, mechanics of soft materials and structures, Reversible, Symmetry Breaking},
pubstate = {published},
tppubtype = {article}
}
Buckling-induced reversible symmetry breaking and amplification of chirality using macro- and microscale supported cellular structures is described. Guided by extensive theoretical analysis, cellular structures are rationally designed, in which buckling induces a reversible switching between achiral and chiral configurations. Additionally, it is demonstrated that the proposed mechanism can be generalized over a wide range of length scales, geometries, materials, and stimuli.