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Ramasamy C, Low HY. Triple and Quadruple Surface Pattern Memories in Nanoimprinted Polymer Blends. ACS APPLIED MATERIALS & INTERFACES 2023; 15:2357-2367. [PMID: 36546466 DOI: 10.1021/acsami.2c17381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Trigger-responsive surfaces with multiple surface properties have wide-ranging application potential from surfaces with trigger-responsive fluid flow to cell culture to optical effects; such surfaces can be achieved through surface morphological changes. Although multiple shape-memory effects are successful in bulk polymers, there is limited programing and recovery of multiple surface memories due to the challenges in fabricating multiple surface topographies with good controllability. Here, we report the synergy between the polymer blend formulation and the thermal nanoimprinting process to achieve multiple microtopography memories. A series of immiscible blends consisting of poly(caprolactone) (PCL) and polyethylene (PE) with distinct thermal transitions governed by distinct crystallization events were augmented with improved elasticity through preferential cross-linking in the polymer blend. The effect of preferential cross-linking by dicumyl peroxide on the elastic property of the PCL/PE has been found to be nonlinearly dependent on the blend composition. This approach enabled triple and quadruple surface pattern fixity and recovery in nanoimprinted PCL/PE blends. Specifically, we demonstrated the recovery of a micropillar structure (diameter: 20 μm and height: 10 μm) from a hierarchical micrograting topography (width: 2 μm and height: 2 μm) when exposed to a thermal stimulus at 60 °C for 180 s. Furthermore, we also demonstrated the recovery of a deformed micrograting followed by a secondary recovery of the micropillar structure.
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Affiliation(s)
- Chitrakala Ramasamy
- Engineering Product Development, Singapore University of Technology and Design, Singapore487372, Singapore
| | - Hong Yee Low
- Engineering Product Development, Singapore University of Technology and Design, Singapore487372, Singapore
- Digital Manufacturing and Design Centre, Singapore University of Technology and Design, Singapore487372, Singapore
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2
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Li W, Liu J, Chen L, Wei W, Qian K, Liu Y, Leng J. Application and Development of Shape Memory Micro/Nano Patterns. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105958. [PMID: 35362270 DOI: 10.1002/smll.202105958] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/12/2021] [Indexed: 06/14/2023]
Abstract
Shape memory polymers (SMPs) are a class of smart materials that change shape when stimulated by environmental stimuli. Different from the shape memory effect at the macro level, the introduction of micro-patterning technology into SMPs strengthens the exploration of the shape memory effect at the micro/nano level. The emergence of shape memory micro/nano patterns provides a new direction for the future development of smart polymers, and their applications in the fields of biomedicine/textile/micro-optics/adhesives show huge potential. In this review, the authors introduce the types of shape memory micro/nano patterns, summarize the preparation methods, then explore the imminent and potential applications in various fields. In the end, their shortcomings and future development direction are also proposed.
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Affiliation(s)
- Wenbing Li
- Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi, 214122, P. R. China
| | - Junhao Liu
- Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi, 214122, P. R. China
| | - Lei Chen
- Department of Biomedical Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen, 518055, P. R. China
| | - Wanting Wei
- Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi, 214122, P. R. China
| | - Kun Qian
- Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi, 214122, P. R. China
| | - Yanju Liu
- Department of Astronautical Science and Mechanics, Harbin Institute of Technology (HIT), Harbin, 150001, P. R. China
| | - Jinsong Leng
- Centre for Composite Materials and Structures, Harbin Institute of Technology (HIT), Harbin, 150080, P. R. China
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Electrical and thermal stimuli responsive thermoplastic shape memory polymer composites containing rGO, Fe3O4 and rGO–Fe3O4 fillers. Polym Bull (Berl) 2021. [DOI: 10.1007/s00289-020-03427-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Shi X, Zhang Y, Wu D, Wu T, Jiang S, Jiao Y, Wu S, Zhang Y, Hu Y, Ding W, Chu J. Femtosecond Laser-Assisted Top-Restricted Self-Growth Re-Entrant Structures on Shape Memory Polymer for Dynamic Pressure Resistance. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12346-12356. [PMID: 32967422 DOI: 10.1021/acs.langmuir.0c02335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Bioinspired surface material with re-entrant texture has been proven effective in exhibiting good pressure resistance to droplets with low surface tension under static conditions. In this work, we combined femtosecond laser cutting with shape memory polymer (SMP) and tape to fabricate re-entrant micropillar arrays by proposing a top-restricted self-growth (TRSG) strategy. Our proposed TRSG strategy simplifies the fabrication process and improves the processing efficiency of the re-entrant structure-based surface material. The structural parameters of the re-entrant micropillar array (microdisk diameter D, center-to-center distance P, and height H) can be adjusted through our TRSG processing method. To better characterize the anti-infiltration ability of various re-entrant micropillars, we studied the dynamic process of ethylene glycol droplet deformation by applying external vertical vibration to the surface material. Three parameters (vibration mode, amplitude, and frequency) of the external excitation and structural parameters of the re-entrant micropillar array were systemically investigated. We found that the surface material had better dynamic pressure resistance when P and D of the re-entrant texture were 650 and 500 μm, respectively, after heating for 6 min. This work provides new insights into the preparation and characterization of the surface material, which may find potential applications in microdroplet manipulation, drug testing, and biological sensors.
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Affiliation(s)
- Xiangchao Shi
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Yachao Zhang
- CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Dong Wu
- CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Tao Wu
- Department of Modern Mechanics, University of Science and Technology of China, Hefei 230026, China
| | - Shaojun Jiang
- CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Yunlong Jiao
- Institute of Tribology, Hefei University of Technology, Hefei 230009, China
| | - Sizhu Wu
- School of Instrument Science and Optoelectronics Engineering, Hefei University of Technology, Hefei 230009, China
| | - Yiyuan Zhang
- CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Yanlei Hu
- CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
| | - Weiping Ding
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230026, China
| | - Jiaru Chu
- CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
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Hot Embossing of Micro-Pyramids into Thermoset Thiol-Ene Film. Polymers (Basel) 2020; 12:polym12102291. [PMID: 33036296 PMCID: PMC7600293 DOI: 10.3390/polym12102291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/02/2020] [Accepted: 10/05/2020] [Indexed: 11/16/2022] Open
Abstract
This paper presents the first attempt to texturize a fully crosslinked thermoset shape memory polymer using a hot embossing technique. UV-cured thiol-ene films were successfully embossed with anisotropically-etched Si (100) stamps at a temperature of 100 °C, which is about 50 °C above the glass transition temperature of the polymer. The low storage modulus of the polymer in a rubbery state allowed us to permanently emboss random micro-pyramidal patterns onto the surface of the film with high fidelity by applying 30 MPa pressure for 1 h. Atomic force microscopy (AFM) investigation showed perfect replication of the stamp micropattern with typical height of the largest inverted pyramids close to 0.7 µm and lateral dimensions in the range of 1–2 µm. Changes in surface roughness parameters of the embossed thiol-ene films after annealing them at 100 °C for 1 h or storing for 2 months in air at standard room conditions were negligible. The achieved results open new perspectives for the simple and inexpensive hot embossing technique to be applied for the micropatterning of prepolymerized thermoset shape memory films as an alternative to micropatterning using UV casting.
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Pishvar M, Harne RL. Foundations for Soft, Smart Matter by Active Mechanical Metamaterials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001384. [PMID: 32999844 PMCID: PMC7509744 DOI: 10.1002/advs.202001384] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/17/2020] [Indexed: 05/22/2023]
Abstract
Emerging interest to synthesize active, engineered matter suggests a future where smart material systems and structures operate autonomously around people, serving diverse roles in engineering, medical, and scientific applications. Similar to biological organisms, a realization of active, engineered matter necessitates functionality culminating from a combination of sensory and control mechanisms in a versatile material frame. Recently, metamaterial platforms with integrated sensing and control have been exploited, so that outstanding non-natural material behaviors are empowered by synergistic microstructures and controlled by smart materials and systems. This emerging body of science around active mechanical metamaterials offers a first glimpse at future foundations for autonomous engineered systems referred to here as soft, smart matter. Using natural inspirations, synergy across disciplines, and exploiting multiple length scales as well as multiple physics, researchers are devising compelling exemplars of actively controlled metamaterials, inspiring concepts for autonomous engineered matter. While scientific breakthroughs multiply in these fields, future technical challenges remain to be overcome to fulfill the vision of soft, smart matter. This Review surveys the intrinsically multidisciplinary body of science targeted to realize soft, smart matter via innovations in active mechanical metamaterials and proposes ongoing research targets that may deliver the promise of autonomous, engineered matter to full fruition.
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Affiliation(s)
- Maya Pishvar
- Department of Mechanical and Aerospace EngineeringThe Ohio State UniversityColumbusOH43210USA
| | - Ryan L. Harne
- Department of Mechanical and Aerospace EngineeringThe Ohio State UniversityColumbusOH43210USA
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Surface Structures, Particles, and Fibers of Shape-Memory Polymers at Micro-/Nanoscale. ADVANCES IN POLYMER TECHNOLOGY 2020. [DOI: 10.1155/2020/7639724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Shape-memory polymers (SMPs) are one kind of smart polymers and can change their shapes in a predefined manner under stimuli. Shape-memory effect (SME) is not a unique ability for specific polymeric materials but results from the combination of a tailored shape-memory creation procedure (SMCP) and suitable molecular architecture that consists of netpoints and switching domains. In the last decade, the trend toward the exploration of SMPs to recover structures at micro-/nanoscale occurs with the development of SMPs. Here, the progress of the exploration in micro-/nanoscale structures, particles, and fibers of SMPs is reviewed. The preparation method, SMCP, characterization of SME, and applications of surface structures, free-standing particles, and fibers of SMPs at micro-/nanoscale are summarized.
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Haryadi BM, Hafner D, Amin I, Schubel R, Jordan R, Winter G, Engert J. Nonspherical Nanoparticle Shape Stability Is Affected by Complex Manufacturing Aspects: Its Implications for Drug Delivery and Targeting. Adv Healthc Mater 2019; 8:e1900352. [PMID: 31410996 DOI: 10.1002/adhm.201900352] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/05/2019] [Indexed: 02/04/2023]
Abstract
The shape of nanoparticles is known recently as an important design parameter influencing considerably the fate of nanoparticles with and in biological systems. Several manufacturing techniques to generate nonspherical nanoparticles as well as studies on in vitro and in vivo effects thereof have been described. However, nonspherical nanoparticle shape stability in physiological-related conditions and the impact of formulation parameters on nonspherical nanoparticle resistance still need to be investigated. To address these issues, different nanoparticle fabrication methods using biodegradable polymers are explored to produce nonspherical nanoparticles via the prevailing film-stretching method. In addition, systematic comparisons to other nanoparticle systems prepared by different manufacturing techniques and less biodegradable materials (but still commonly utilized for drug delivery and targeting) are conducted. The study evinces that the strong interplay from multiple nanoparticle properties (i.e., internal structure, Young's modulus, surface roughness, liquefaction temperature [glass transition (Tg ) or melting (Tm )], porosity, and surface hydrophobicity) is present. It is not possible to predict the nonsphericity longevity by merely one or two factor(s). The most influential features in preserving the nonsphericity of nanoparticles are existence of internal structure and low surface hydrophobicity (i.e., surface-free energy (SFE) > ≈55 mN m-1 , material-water interfacial tension <6 mN m-1 ), especially if the nanoparticles are soft (<1 GPa), rough (Rrms > 10 nm), porous (>1 m2 g-1 ), and in possession of low bulk liquefaction temperature (<100 °C). Interestingly, low surface hydrophobicity of nanoparticles can be obtained indirectly by the significant presence of residual stabilizers. Therefore, it is strongly suggested that nonsphericity of particle systems is highly dependent on surface chemistry but cannot be appraised separately from other factors. These results and reviews allot valuable guidelines for the design and manufacturing of nonspherical nanoparticles having adequate shape stability, thereby appropriate with their usage purposes. Furthermore, they can assist in understanding and explaining the possible mechanisms of nonspherical nanoparticles effectivity loss and distinctive material behavior at the nanoscale.
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Affiliation(s)
- Bernard Manuel Haryadi
- Pharmaceutical Technology and BiopharmaceuticsDepartment of PharmacyLudwig‐Maximilians‐Universität München Butenandtstraße 5 81377 Munich Germany
| | - Daniel Hafner
- Department of ChemistryDresden University of Technology Mommsenstraße 4 01069 Dresden Germany
| | - Ihsan Amin
- Department of ChemistryDresden University of Technology Mommsenstraße 4 01069 Dresden Germany
| | - Rene Schubel
- Department of ChemistryDresden University of Technology Mommsenstraße 4 01069 Dresden Germany
| | - Rainer Jordan
- Department of ChemistryDresden University of Technology Mommsenstraße 4 01069 Dresden Germany
| | - Gerhard Winter
- Pharmaceutical Technology and BiopharmaceuticsDepartment of PharmacyLudwig‐Maximilians‐Universität München Butenandtstraße 5 81377 Munich Germany
| | - Julia Engert
- Pharmaceutical Technology and BiopharmaceuticsDepartment of PharmacyLudwig‐Maximilians‐Universität München Butenandtstraße 5 81377 Munich Germany
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Castillo-Cruz O, Avilés F, Vargas-Coronado R, Cauich-Rodríguez JV, Chan-Chan LH, Sessini V, Peponi L. Mechanical properties of l-lysine based segmented polyurethane vascular grafts and their shape memory potential. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 102:887-895. [PMID: 31147060 DOI: 10.1016/j.msec.2019.04.073] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 04/06/2019] [Accepted: 04/23/2019] [Indexed: 12/31/2022]
Abstract
Segmented polyurethanes based on polycaprolactone, 4,4 (metylene-bis-cyclohexyl) isocyanate, and l-lysine were synthesized, manufactured as small vascular grafts and characterized according to ISO 7198 standard for cardiovascular implants-tubular vascular prosthesis. In terms of mechanical properties, the newly synthesized polyurethane films exhibited lower secant modulus than Tecoflex™ SG 80A, a well-known medical grade polyurethane. Similarly, when tested as grafts, the l-lysine-based polyurethane exhibited lower longitudinal failure load (11.5 N vs. 116 N), lower circumferential failure load per unit length (5.67 N/mm vs. 14.0 N/mm) and lower suture forces for both nylon (13.3 N vs. 24.0 N) and silk (14.0 N vs. 19.3 N) when compared to Tecoflex™ SG 80A grafts. l-Lysine-based graft exhibited a burst strength of 3620 mmHg (482.6 kPa) and a compliance of 0.16%/mmHg. The cell adhesion was demonstrated with NIH/3T3 fibroblasts where cell adhesion was observed on both films and grafts, while cell alignment was observed only on the grafts. The mechanical properties of this polyurethane and the possibility of strain-induced PCL crystals as the switching phase for shape memory materials, allowed a strain recovery ratio and a strain fixity ratio with values higher than 95% and 90%, respectively, with a repeatability of the shape-memory properties up to 4 thermo-mechanical cycles. Overall, the properties of lysine-based polyurethanes are suitable for large diameter vascular grafts where cell alignment can be controlled by their shape memory potential.
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Affiliation(s)
- O Castillo-Cruz
- Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 # 130 x 32 y 34, Col. Chuburná de Hidalgo, 97205 Mérida, Yucatán, Mexico
| | - F Avilés
- Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 # 130 x 32 y 34, Col. Chuburná de Hidalgo, 97205 Mérida, Yucatán, Mexico
| | - R Vargas-Coronado
- Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 # 130 x 32 y 34, Col. Chuburná de Hidalgo, 97205 Mérida, Yucatán, Mexico
| | - J V Cauich-Rodríguez
- Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 # 130 x 32 y 34, Col. Chuburná de Hidalgo, 97205 Mérida, Yucatán, Mexico.
| | - L H Chan-Chan
- CONACyT-Universidad de Sonora, Blvd. Luis Encinas y Rosales, Centro, C.P. 83000, Hermosillo, Sonora, Mexico
| | - V Sessini
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain
| | - L Peponi
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain
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Abstract
In this work, surface microstructurization was coupled with shape-memory polymer to generate reversibly tunable surface properties. A photopolymerizable thiol-ene composition comprising a mixture of pentaerythritol tetrakis(3-mercaptopropionate) (PETMP), 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TTT) and 2,2-dimethoxy-2-phenylacetophenone (DMPA) was used to prepare microstructured thiol-ene shape-memory film via casting and UV polymerization on the electron beam lithography fabricated arrays of 1 µm and 2 µm square pits. The mechanical deformation via compression and recovery of the surface microstructure were investigated. Results show that, after heat treatment of the deformed thiol-ene film, the recovery yields for microstructures were not worse than 90% ± 2% and 93% ± 2% for structures imprinted with 1 µm and 2 µm square pit micro imprint stamps. Additionally, heat treatment of deformed thiol-ene film resulted in the recovery of intense diffraction colors and laser diffraction patterns. This study opens up an avenue of incorporating microstructured shape-memory films for new products, e.g., optical security devices, superhydrophobic coatings, medical diagnostics and biosensors.
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Zhang D, Cheng Z, Liu Y. Smart Wetting Control on Shape Memory Polymer Surfaces. Chemistry 2018; 25:3979-3992. [DOI: 10.1002/chem.201804192] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Indexed: 01/10/2023]
Affiliation(s)
- Dongjie Zhang
- MIIT Key Laboratory of Critical Materials Technology for New Energy, Conversion and StorageSchool of Chemistry and Chemical EngineeringHarbin Institute of Technology Harbin 150001 P.R. China
| | - Zhongjun Cheng
- Academy of Fundamental and Interdisciplinary SciencesHarbin Institute of Technology Harbin 150090 P.R. China
| | - Yuyan Liu
- MIIT Key Laboratory of Critical Materials Technology for New Energy, Conversion and StorageSchool of Chemistry and Chemical EngineeringHarbin Institute of Technology Harbin 150001 P.R. China
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Lee WL, Low HY, Ortiz C. Geometry-dependent compressive responses in nanoimprinted submicron-structured shape memory polyurethane. SOFT MATTER 2017; 13:3314-3327. [PMID: 28418057 DOI: 10.1039/c7sm00574a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
High resolution surface textures, when rationally designed, provide an attractive surface engineering approach to enhance surface functionalities. Designing smart surfaces by coupling surface texture with shape memory polymers has garnered attention in achieving tunable mechanical properties. We investigate the structure-mechanical property relationships for programmable, shape-memorizing submicron-scale pillar arrays subjected to flat-punch compression. The geometrically-dependent deformation of structured surfaces with two different aspect ratios (250 nm-pillars 1 : 1 and 550 nm-pillars 2.4 : 1) were investigated, and their moduli were found to be lower than that of non-patterned surface. From finite element analysis, the pillar deformation is correlated to a mechanistic transition from a discrete, unidirectional compression of 250 nm-pillars to lateral constraints caused by interpillar contact in 550 nm-pillars. This lateral pillar-pillar contact in the 550 nm-pillars resulted in an increased and maximum strain-dependent modulus but lower elastic recovery and energy dissipation as compared with the 250 nm-pillars. Furthermore, the compressive responses of temporarily shaped pillars (programmed by stretching) were compared with the permanently shaped pillars. The extent of lateral constraints controlled by pillar shape and spacing in 550 nm-pillars was responsible for the modulus differences between the original and stretched patterns, whereas the modulus of 250 nm-pillars remained as a constant value with different levels of stretching. This study provides mechanistic insights into how the mechanical behavior can be modulated by designing the aspect ratio of shape memory pillar arrays and by programming the surface geometry, thus revealing the potential of developing ingenious designs of responsive surfaces sensitive to mechanical deformation.
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Affiliation(s)
- Wei Li Lee
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
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Chen Y, Zhao Z, Karim A, Weiss RA. Shape Memory of Microscale and Nanoscale Imprinted Patterns on a Supramolecular Polymer Compound. Macromol Rapid Commun 2016; 37:1932-1938. [DOI: 10.1002/marc.201600362] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 08/15/2016] [Indexed: 12/19/2022]
Affiliation(s)
- Ying Chen
- Department of Polymer Engineering University of Akron Akron OH 44325 USA
| | - Zhiyang Zhao
- Department of Polymer Engineering University of Akron Akron OH 44325 USA
| | - Alamgir Karim
- Department of Polymer Engineering University of Akron Akron OH 44325 USA
| | - R. A. Weiss
- Department of Polymer Engineering University of Akron Akron OH 44325 USA
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