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17 pages, 251 KB  
Article
Rebirth, Shapeshifting, and Activism in the Work of Latinx Undocupoets
by Daniel Enrique Pérez
Humanities 2025, 14(9), 182; https://doi.org/10.3390/h14090182 - 17 Sep 2025
Viewed by 1001
Abstract
This essay is an analysis of poetry written by Latinx Undocupoets in the United States. It focuses on three contemporary poets—Javier O. Huerta, Yosimar Reyes, and Javier Zamora. The author examines the way these poets navigate borderland identities by cultivating cultural mestizaje to [...] Read more.
This essay is an analysis of poetry written by Latinx Undocupoets in the United States. It focuses on three contemporary poets—Javier O. Huerta, Yosimar Reyes, and Javier Zamora. The author examines the way these poets navigate borderland identities by cultivating cultural mestizaje to advance a political project, where consciousness-raising and advocating for those who cross or are crossed by borders are the priorities. The author argues that three common themes related to transformation appear in the work of Undocupoets: rebirth, shapeshifting, and activism. These poets transform themselves and their communities by engaging in differential movement and relocating marginalized individuals and communities to positive social locations while portraying them in their full complexity—a postnationalist perspective that manifests itself in a borderlands framework. The author demonstrates how these writers formulate decolonial imaginaries and differential consciousness to relocate migrants and undocumented people to social locations that transcend the negative stereotypes that have historically shaped their identities and lived experiences. Through rebirth, shapeshifting, and activism, Undocupoets enact a form of agency and present new ways of seeing and understanding the migrant experience. Full article
(This article belongs to the Special Issue Hybridity and Border Crossings in Contemporary North American Poetry)
38 pages, 8196 KB  
Review
Morph and Function: Exploring Origami-Inspired Structures in Versatile Robotics Systems
by Tran Vy Khanh Vo, Tan Kai Noel Quah, Li Ting Chua and King Ho Holden Li
Micromachines 2025, 16(9), 1047; https://doi.org/10.3390/mi16091047 - 13 Sep 2025
Viewed by 2903
Abstract
The art of folding paper, named “origami”, has transformed from serving religious and cultural purposes to various educational and entertainment purposes in the modern world. Significantly, the fundamental folds and creases in origami, which enable the creation of 3D structures from a simple [...] Read more.
The art of folding paper, named “origami”, has transformed from serving religious and cultural purposes to various educational and entertainment purposes in the modern world. Significantly, the fundamental folds and creases in origami, which enable the creation of 3D structures from a simple flat sheet with unique crease patterns, serve as a great inspiration in engineering applications such as deployable mechanisms for space exploration, self-folding structures for exoskeletons and surgical procedures, micro-grippers, energy absorption, and programmable robotic morphologies. Therefore, this paper will provide a systematic review of the state-of-the-art origami-inspired structures that have been adopted and exploited in robotics design and operation, called origami-inspired robots (OIRs). The advantages of the flexibility and adaptability of these folding mechanisms enable robots to achieve agile mobility and shape-shifting capabilities that are suited to diverse tasks. Furthermore, the inherent compliance structure, meaning that stiffness can be tuned from rigid to soft with different folding states, allows these robots to perform versatile functions, ranging from soft interactions to robust manipulation and a high-DOF system. In addition, the potential to simplify the fabrication and assembly processes, together with its integration into a wide range of actuation systems, further broadens its capabilities. However, these mechanisms increase the complexity in theoretical analysis and modelling, as well as posing a challenge in control algorithms when the robot’s DOF and reconfigurations are significantly increased. By leveraging the principles of folding and integrating actuation and design strategies, these robots can adapt their shapes, stiffness, and functionality to meet the demands of diverse tasks and environments, offering significant advantages over traditional rigid robots. Full article
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18 pages, 18493 KB  
Article
Modular Snake-like Robot Designed for On-Site Reconfiguration in Space Exploration
by Ning Zhao, Sikai Zhao, Tianjiao Zheng, Jian Qi, Zhiyuan Yang, Xin Sui, Kai Han, Hang Luo, Nanlin Zhou, Jie Zhao and Yanhe Zhu
Biomimetics 2025, 10(5), 293; https://doi.org/10.3390/biomimetics10050293 - 6 May 2025
Cited by 1 | Viewed by 1475
Abstract
Research on modular robots for space exploration has primarily focused on reconfiguration, with limited attention given to the maneuverability in space environment, which is essential for harnessing the advantages of reconfiguration. In this paper, a modular snake-like robot (MSR) is designed, which is [...] Read more.
Research on modular robots for space exploration has primarily focused on reconfiguration, with limited attention given to the maneuverability in space environment, which is essential for harnessing the advantages of reconfiguration. In this paper, a modular snake-like robot (MSR) is designed, which is expected to emulate a snake to navigate complex environments and employ the reconfiguration capability for on-site shape-shifting. To this end, a snake-like motion analysis and planning method is proposed for MSR. Firstly, we explore the feasibility of utilizing modules in realizing snake-like motion, including functional compatibility and structural constraints. Secondly, we analyze the kinematics of MSR and design joint coordination motion schemes to meet the requirements of snake-like motion. Finally, a path planning method based on reinforcement learning is proposed, which fully considers the motion characteristics and the structural constraints. Through motion analysis and planning, a balance between environmental adaptability and versatility can be achieved. Simulations of comparisons and potential applications further demonstrate the significant advantages of MSR in space exploration. Full article
(This article belongs to the Section Locomotion and Bioinspired Robotics)
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15 pages, 568 KB  
Article
(Re)viewing Postsecularity Through the Pragmatic Pursuits of New Religious Movements in India
by Vikram Kapoor
Religions 2025, 16(2), 157; https://doi.org/10.3390/rel16020157 - 30 Jan 2025
Cited by 1 | Viewed by 2529
Abstract
In the contemporary postsecular context, where the influence of religion has become increasingly significant, this study explores the substantial influence of New Religious Movements (NRMs) in India. Focusing on Brahma Kumaris (BKs), a prominent NRM, this study examines their role as proponents of [...] Read more.
In the contemporary postsecular context, where the influence of religion has become increasingly significant, this study explores the substantial influence of New Religious Movements (NRMs) in India. Focusing on Brahma Kumaris (BKs), a prominent NRM, this study examines their role as proponents of social change across various public spheres in modern society. The BKs’ deviation from traditional religious doctrines, their emphasis on self-transformation, and their capacity to adapt to contemporary challenges render them particularly relevant in the postsecular context. This study analyzes the pragmatic approach that BKs employ to engage with and assert their influence in contemporary public life. Specifically, it delineates five critical processes that underpin the organization’s pragmatic pursuits: detraditionalization, synergism, gender sensitization, agro-spiritualism, and digitalization. By subverting varied normativities and contesting the religious/secular dyad through their pragmatic pursuits, the BKs illuminate the shapeshifting edges and fluid integration of religion and secularity within the contemporary postsecular milieu. Full article
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15 pages, 2313 KB  
Article
Four-Dimensional Printing of Multi-Material Origami and Kirigami-Inspired Hydrogel Self-Folding Structures
by Divambal Appavoo, Nilab Azim, Maged Elshatoury, Dennis-Xavier Antony, Swaminathan Rajaraman and Lei Zhai
Materials 2024, 17(20), 5028; https://doi.org/10.3390/ma17205028 - 15 Oct 2024
Cited by 3 | Viewed by 2808
Abstract
Four-dimensional printing refers to a process through which a 3D printed object transforms from one structure into another through the influence of an external energy input. Self-folding structures have been extensively studied to advance 3D printing technology into 4D using stimuli-responsive polymers. Designing [...] Read more.
Four-dimensional printing refers to a process through which a 3D printed object transforms from one structure into another through the influence of an external energy input. Self-folding structures have been extensively studied to advance 3D printing technology into 4D using stimuli-responsive polymers. Designing and applying self-folding structures requires an understanding of the material properties so that the structural designs can be tailored to the targeted applications. Poly(N-iso-propylacrylamide) (PNIPAM) was used as the thermo-responsive material in this study to 3D print hydrogel samples that can bend or fold with temperature changes. A double-layer printed structure, with PNIPAM as the self-folding layer and polyethylene glycol (PEG) as the supporting layer, provided the mechanical robustness and overall flexibility to accommodate geometric changes. The mechanical properties of the multi-material 3D printing were tested to confirm the contribution of the PEG support to the double-layer system. The desired folding of the structures, as a response to temperature changes, was obtained by adding kirigami-inspired cuts to the design. An excellent shape-shifting capability was obtained by tuning the design. The experimental observations were supported by COMSOL Multiphysics® software simulations, predicting the control over the folding of the double-layer systems. Full article
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14 pages, 3747 KB  
Article
The Exponential Shapeshifting Response of N-Vinylcaprolactam Hydrogel Bilayers Due to Temperature Change for Potential Minimally Invasive Surgery
by Billy Shu Hieng Tie, Mark Daly, Shuo Zhuo, Elaine Halligan, Gavin Keane, Joseph Geever and Luke Geever
J. Funct. Biomater. 2024, 15(9), 242; https://doi.org/10.3390/jfb15090242 - 24 Aug 2024
Cited by 3 | Viewed by 1857
Abstract
Poly (N-vinylcaprolactam) (PNVCL) and poly (N-isopropylacrylamide) (PNIPAm) are two popular negatively temperature-responsive hydrogels, due to their biocompatibility, softness, hydrophilicity, superabsorbency, viscoelasticity, and near-physiological lower critical solution temperature (LCST). These characteristics make them ideal for biomedical applications. When combined with other materials, hydrogel expansion [...] Read more.
Poly (N-vinylcaprolactam) (PNVCL) and poly (N-isopropylacrylamide) (PNIPAm) are two popular negatively temperature-responsive hydrogels, due to their biocompatibility, softness, hydrophilicity, superabsorbency, viscoelasticity, and near-physiological lower critical solution temperature (LCST). These characteristics make them ideal for biomedical applications. When combined with other materials, hydrogel expansion induces the morphing of the assembly due to internal stress differences. Our recent developments in NVCL hydrogel, enhanced by nanoclay incorporation, have driven us to the creation of a bilayer structure to study its shapeshifting response across various temperatures. This study focused on the bending behaviour of bilayer samples composed of an active hydrogel layer and a passive non-swellable layer. Using photopolymerisation, circular discs and rectangular bilayer samples of varying sizes were fabricated. Homogeneous circular samples demonstrated that hydrogel density increased proportionally with temperature, with the swelling ratio exhibiting two distinct rates of change below and above its LCST. In bilayer samples, the volume of the passive layer influenced bending, and its optimal volume was identified. The investigation revealed that geometry affected the overall bending effect due to changes in the passive layer stiffness. Lastly, a temperature-responsive gripper capable of picking up objects several times its own weight was demonstrated, highlighting the potential of NVCL hydrogels as bioactuators for minimally invasive surgery. Full article
(This article belongs to the Special Issue Design and Synthesis Composites for Biomedical Application)
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23 pages, 11342 KB  
Article
Geometric Implications of Photodiode Arrays on Received Power Distribution in Mobile Underwater Optical Wireless Communication
by Tharuka Govinda Waduge, Boon-Chong Seet and Kay Vopel
Sensors 2024, 24(11), 3490; https://doi.org/10.3390/s24113490 - 28 May 2024
Cited by 5 | Viewed by 1930
Abstract
Underwater optical wireless communication (UOWC) has gained interest in recent years with the introduction of autonomous and remotely operated mobile systems in blue economic ventures such as offshore food production and energy generation. Here, we devised a model for estimating the received power [...] Read more.
Underwater optical wireless communication (UOWC) has gained interest in recent years with the introduction of autonomous and remotely operated mobile systems in blue economic ventures such as offshore food production and energy generation. Here, we devised a model for estimating the received power distribution of diffused line-of-sight mobile optical links, accommodating irregular intensity distributions beyond the beam-spread angle of the emitter. We then used this model to conduct a spatial analysis investigating the parametric influence of the placement, orientation, and angular spread of photodiodes in array-based receivers on the mobile UOWC links in different Jerlov seawater types. It revealed that flat arrays were best for links where strict alignment could be maintained, whereas curved arrays performed better spatially but were not always optimal. Furthermore, utilizing two or more spectrally distinct wavelengths and more bandwidth-efficient modulation may be preferred for received-signal intensity-based localization and improving link range in clearer oceans, respectively. Considering the geometric implications of the array of receiver photodiodes for mobile UOWCs, we recommend the use of dynamically shape-shifting array geometries. Full article
(This article belongs to the Special Issue Underwater Vision Sensing System)
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21 pages, 1787 KB  
Review
Landscape and Treatment Options of Shapeshifting Small Cell Lung Cancer
by Yijun Gu and Claudia A. Benavente
J. Clin. Med. 2024, 13(11), 3120; https://doi.org/10.3390/jcm13113120 - 26 May 2024
Cited by 3 | Viewed by 4119
Abstract
Small cell lung cancer (SCLC) is a deadly neuroendocrine malignancy, notorious for its rapid tumor growth, early metastasis, and relatively “cold” immune environment. Only standard chemotherapies and a few immune checkpoint inhibitors have been approved for SCLC treatment, revealing an urgent need for [...] Read more.
Small cell lung cancer (SCLC) is a deadly neuroendocrine malignancy, notorious for its rapid tumor growth, early metastasis, and relatively “cold” immune environment. Only standard chemotherapies and a few immune checkpoint inhibitors have been approved for SCLC treatment, revealing an urgent need for novel therapeutic approaches. Moreover, SCLC has been recently recognized as a malignancy with high intratumoral and intertumoral heterogeneity, which explains the modest response rate in some patients and the early relapse. Molecular subtypes defined by the expression of lineage-specific transcription factors (ASCL1, NEUROD1, POU2F3, and, in some studies, YAP1) or immune-related genes display different degrees of neuroendocrine differentiation, immune cell infiltration, and response to treatment. Despite the complexity of this malignancy, a few biomarkers and targets have been identified and many promising drugs are currently undergoing clinical trials. In this review, we integrate the current progress on the genomic landscape of this shapeshifting malignancy, the characteristics and treatment vulnerabilities of each subtype, and promising drugs in clinical phases. Full article
(This article belongs to the Section Oncology)
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28 pages, 27240 KB  
Article
PARTS—A 2D Self-Reconfigurable Programmable Mechanical Structure
by Michael Gerbl, Michael Pieber, Emanuel Ulrich and Johannes Gerstmayr
Robotics 2024, 13(5), 77; https://doi.org/10.3390/robotics13050077 - 14 May 2024
Cited by 3 | Viewed by 5715
Abstract
Modular self-reconfigurable robots hold the promise of being capable of performing a wide variety of tasks. However, many systems fall short of either delivering this promised functionality due to constraints in system architecture or validating it on functional hardware prototypes. This paper demonstrates [...] Read more.
Modular self-reconfigurable robots hold the promise of being capable of performing a wide variety of tasks. However, many systems fall short of either delivering this promised functionality due to constraints in system architecture or validating it on functional hardware prototypes. This paper demonstrates the functional capabilities of the Planar Adaptive Robot with Triangular Structure (PARTS) and documents the versatility of this robot system using a holistic approach that combines simulations and hardware demonstrations on a prototype with nine fabricated modules. PARTS is a two-dimensional modular robot consisting of modules with a shape-shifting triangular geometry capable of forming adaptable space-covering structures. Meta-modules and mesh restructuring techniques are presented as methods for achieving topological self-reconfiguration. The feasibility of these methods is demonstrated by applying them on a simulated reconfiguration example of 62 modules. The paper showcases the versatility of PARTS on the hardware prototype using task-specific configurations, including locomotion using a meta-module and a walker configuration, module-module interaction by establishing a bridge between two separated module clusters, and interaction with the environment using a gripper and supporting structure configuration. The results validate the versatility and emphasize the potential of the system’s design concept, motivating the transfer of the hardware architecture to the third dimension. Full article
(This article belongs to the Section Intelligent Robots and Mechatronics)
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13 pages, 2986 KB  
Article
NIR-Mediated Deformation from a CNT-Based Bilayer Hydrogel
by Shijun Long, Chang Liu, Han Ren, Yali Hu, Chao Chen, Yiwan Huang and Xuefeng Li
Polymers 2024, 16(8), 1152; https://doi.org/10.3390/polym16081152 - 19 Apr 2024
Cited by 4 | Viewed by 1956
Abstract
Shape-shifting polymers are widely used in various fields such as intelligent switches, soft robots and sensors, which require both multiple stimulus-response functions and qualified mechanical strength. In this study, a novel near-infrared-light (NIR)-responsible shape-shifting hydrogel system was designed and fabricated through embedding vinylsilane-modified [...] Read more.
Shape-shifting polymers are widely used in various fields such as intelligent switches, soft robots and sensors, which require both multiple stimulus-response functions and qualified mechanical strength. In this study, a novel near-infrared-light (NIR)-responsible shape-shifting hydrogel system was designed and fabricated through embedding vinylsilane-modified carbon nanotubes (CNTs) into particle double-network (P-DN) hydrogels by micellar copolymerisation. The dispersed brittle Poly(sodium 2-acrylamido-2-methylpropane-1-sulfonate) (PNaAMPS) network of the microgels can serve as sacrificial bonds to toughen the hydrogels, and the CNTs endow it with NIR photothermal conversion ability. The results show that the CNTs embedded in the P-DN hydrogels present excellent mechanical strength, i.e., a fracture strength of 312 kPa and a fracture strain of 357%. Moreover, an asymmetric bilayer hydrogel, where the active layer contains CNTs, can achieve 0°–110° bending deformation within 10 min under NIR irradiation and can realise complex deformation movement. This study provides a theoretical and experimental basis for the design and manufacture of photoresponsive soft actuators. Full article
(This article belongs to the Special Issue Advances in Multifunctional Hydrogel, 2nd Edition)
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16 pages, 3428 KB  
Article
Ion-Cross-Linked Hybrid Photochromic Hydrogels with Enhanced Mechanical Properties and Shape Memory Behaviour
by Shijun Long, Fan Chen, Han Ren, Yali Hu, Chao Chen, Yiwan Huang and Xuefeng Li
Polymers 2024, 16(8), 1031; https://doi.org/10.3390/polym16081031 - 10 Apr 2024
Cited by 2 | Viewed by 1741
Abstract
Shape-shifting polymers usually require not only reversible stimuli-responsive ability, but also strong mechanical properties. A novel shape-shifting photochromic hydrogel system was designed and fabricated by embedding hydrophobic spiropyran (SP) into double polymeric network (DN) through micellar copolymerisation. Here, sodium alginate (Alg) and poly [...] Read more.
Shape-shifting polymers usually require not only reversible stimuli-responsive ability, but also strong mechanical properties. A novel shape-shifting photochromic hydrogel system was designed and fabricated by embedding hydrophobic spiropyran (SP) into double polymeric network (DN) through micellar copolymerisation. Here, sodium alginate (Alg) and poly acrylate-co-methyl acrylate-co-spiropyran (P(SA-co-MA-co-SPMA)) were employed as the first network and the second network, respectively, to realise high mechanical strength. After being soaked in the CaCl2 solution, the carboxyl groups in the system underwent metal complexation with Ca2+ to enhance the hydrogel. Moreover, after the hydrogel was exposed to UV-light, the closed isomer of spiropyran in the hydrogel network could be converted into an open zwitterionic isomer merocyanine (MC), which was considered to interact with Ca2+ ions. Interestingly, Ca2+ and UV-light responsive programmable shape of the copolymer hydrogel could recover to its original form via immersion in pure water. Given its excellent metal ion and UV light stimuli-responsive and mechanical properties, the hydrogel has potential applications in the field of soft actuators. Full article
(This article belongs to the Section Smart and Functional Polymers)
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18 pages, 8356 KB  
Review
4D Printing Shape-Morphing Hybrid Biomaterials for Advanced Bioengineering Applications
by Irene Chiesa, Maria Rachele Ceccarini, Silvia Bittolo Bon, Michela Codini, Tommaso Beccari, Luca Valentini and Carmelo De Maria
Materials 2023, 16(20), 6661; https://doi.org/10.3390/ma16206661 - 12 Oct 2023
Cited by 13 | Viewed by 3143
Abstract
Four-dimensional (4D) printing is an innovative additive manufacturing technology used to fabricate structures that can evolve over time when exposed to a predefined environmental stimulus. 4D printed objects are no longer static objects but programmable active structures that accomplish their functions thanks to [...] Read more.
Four-dimensional (4D) printing is an innovative additive manufacturing technology used to fabricate structures that can evolve over time when exposed to a predefined environmental stimulus. 4D printed objects are no longer static objects but programmable active structures that accomplish their functions thanks to a change over time in their physical/chemical properties that usually displays macroscopically as a shapeshifting in response to an external stimulus. 4D printing is characterized by several entangled features (e.g., involved material(s), structure geometry, and applied stimulus entities) that need to be carefully coupled to obtain a favorable fabrication and a functioning structure. Overall, the integration of micro-/nanofabrication methods of biomaterials with nanomaterials represents a promising approach for the development of advanced materials. The ability to construct complex and multifunctional triggerable structures capable of being activated allows for the control of biomedical device activity, reducing the need for invasive interventions. Such advancements provide new tools to biomedical engineers and clinicians to design dynamically actuated implantable devices. In this context, the aim of this review is to demonstrate the potential of 4D printing as an enabling manufacturing technology to code the environmentally triggered physical evolution of structures and devices of biomedical interest. Full article
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10 pages, 225 KB  
Article
Visions of Red Riding Hood: Transformative Bodies in Contemporary Adaptations
by Elizabeth Abele
Humanities 2023, 12(3), 48; https://doi.org/10.3390/h12030048 - 12 Jun 2023
Viewed by 6336
Abstract
Gothic and sexual elements are embedded within both Charles Perrault’s and the Brothers Grimm’s tellings of “Little Red Riding Hood”. When popular culture turned to fairy tales from the late 20th century forward, reimagining them as gothic tales for adults, “Little Red Riding [...] Read more.
Gothic and sexual elements are embedded within both Charles Perrault’s and the Brothers Grimm’s tellings of “Little Red Riding Hood”. When popular culture turned to fairy tales from the late 20th century forward, reimagining them as gothic tales for adults, “Little Red Riding Hood” provided a particularly rich setting. In particular, these adaptations exploited the false binaries within these tales while making more visible the sexual abuse and recovery encoded in the narratives. This essay will first explore the particular gothic qualities within this tale, as well as the shapeshifting nature of the four characters. After establishing how the figure of Red, as well as her motifs, are key to ensemble fairy-tale narratives, I will examine adaptations that directly explore the sexuality and agency of a young woman, as she resists both predators and her family legacy. However, the last section will note that monstrosity, like victimization, can be resisted. Overall, this essay interrogates contemporary film and television adaptations of this tale, with a particular interest in the messages of recovery and agency in these new versions. Full article
(This article belongs to the Special Issue Gothic Adaptation: Intermedial and Intercultural Shape-Shifting)
17 pages, 9869 KB  
Article
Synthesis of NVCL-NIPAM Hydrogels Using PEGDMA as a Chemical Crosslinker for Controlled Swelling Behaviours in Potential Shapeshifting Applications
by Billy Shu Hieng Tie, Elaine Halligan, Shuo Zhuo, Gavin Keane and Luke Geever
Gels 2023, 9(3), 248; https://doi.org/10.3390/gels9030248 - 20 Mar 2023
Cited by 10 | Viewed by 3533
Abstract
Stimuli-responsive hydrogels have recently gained interest within shapeshifting applications due to their capabilities to expand in water and their altering swelling properties when triggered by stimuli, such as pH and heat. While conventional hydrogels lose their mechanical strength during swelling, most shapeshifting applications [...] Read more.
Stimuli-responsive hydrogels have recently gained interest within shapeshifting applications due to their capabilities to expand in water and their altering swelling properties when triggered by stimuli, such as pH and heat. While conventional hydrogels lose their mechanical strength during swelling, most shapeshifting applications require materials to have mechanical strength within a satisfactory range to perform specified tasks. Thus, stronger hydrogels are needed for shapeshifting applications. Poly (N-isopropylacrylamide) (PNIPAm) and poly (N-vinyl caprolactam) (PNVCL) are the most popular thermosensitive hydrogels studied. Their close-to-physiological lower critical solution temperature (LCST) makes them superior candidates in biomedicine. In this study, copolymers made of NVCL and NIPAm and chemically crosslinked using poly (ethylene glycol) dimethacrylate (PEGDMA) were fabricated. Successful polymerisation was proven via Fourier transform infrared spectroscopy (FTIR). The effects of incorporating comonomer and crosslinker on the LCST were found minimal using cloud-point measurements, ultraviolet (UV) spectroscopy, and differential scanning calorimetry (DSC). Formulations that completed three cycles of thermo-reversing pulsatile swelling are demonstrated. Lastly, rheological analysis validated the mechanical strength of PNVCL, which was improved due to the incorporation of NIPAm and PEGDMA. This study showcases potential smart thermosensitive NVCL-based copolymers that can be applied in the biomedical shapeshifting area. Full article
(This article belongs to the Special Issue Advances in Responsive Hydrogels)
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19 pages, 6348 KB  
Article
Strategies for Developing Shape-Shifting Behaviours and Potential Applications of Poly (N-vinyl Caprolactam) Hydrogels
by Shuo Zhuo, Billy Shu Hieng Tie, Gavin Keane and Luke M. Geever
Polymers 2023, 15(6), 1511; https://doi.org/10.3390/polym15061511 - 18 Mar 2023
Cited by 5 | Viewed by 2118
Abstract
Stimuli-responsive hydrogels are one type of smart hydrogel, which can expand/contract in water according to changes in the surrounding environment. However, it is difficult to develop flexible shapeshifting behaviours by using a single hydrogel material. This study exploited a new method to utilise [...] Read more.
Stimuli-responsive hydrogels are one type of smart hydrogel, which can expand/contract in water according to changes in the surrounding environment. However, it is difficult to develop flexible shapeshifting behaviours by using a single hydrogel material. This study exploited a new method to utilise single and bilayer structures to allow hydrogel-based materials to exhibit controllable shape-shifting behaviours. Although other studies have demonstrated similar transformation behaviours, this is the first report of such smart materials developed using photopolymerised N-vinyl caprolactam (NVCL)-based polymers. Our contribution provides a straightforward method in the fabrication of deformable structures. In the presence of water, the bending behaviours (vertex-to-vertex and edge-to-edge) were achieved in monolayer squares. By controlling the content and combination of the NVCL solutions with elastic resin, the bilayer strips were prepared. The expected reversible self-bending and self-helixing behaviours were achieved in specific types of samples. In addition, by limiting the expansion time of the bilayer, the layered flower samples exhibited predictable self-curving shape transformation behaviour in at least three cycles of testing. These structures displayed the capacity of self-transformation, and the value and functionality of the produced components are reflected in this paper. Full article
(This article belongs to the Special Issue Polymer-Based Hydrogel Materials)
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