BIOMACROMOLECULES
·
2023
·
IF 6.2
Yang Yang,E. Liu,Wenli An,Yan Hu,Xuehuan Xia,Shimei Xu
Mimicking the anisotropic structure and environmental adaptation of organisms in nature remains a key objective in the field of hydrogels. However, it has been very challenging due to complex fabrication and confined application only in water. Here, we demonstrate a new strategy of spontaneous fabrication of an anisotropic hydrogel based on our finding in the tropic movement of gelatin toward the Teflon template. The obtained hydrogel exhibits fast response and recovery under temperature stimuli both in aqueous and non-aqueous environments, making use of the approximate transition temperature and opposite phase transition behavior of gelatin and poly(N-isopropylacrylamide) (PNIPAm). Its recovery performance in water is more than 50 times faster than that of the PNIPAm hydrogel. Furthermore, the PNIPAm/gelatin hydrogel can achieve 3D complex deformations, stealth deformation, erasable and reprogrammed surface patterning, and multistage encryption by simply modulating the location and shape of gelatin to achieve an anisotropic structure. The work provides a simple and versatile way to obtain an anisotropic hydrogel with a definite and predictable structure, which is demonstrated across a range of different monomers. It improves the responsive performance and broadens the hydrogel application to the non-aqueous environment. Additionally, this tropic movement of gelatin can be extended for the design of new types of anisotropic materials and thus endows the materials with diverse functionality.
研究领域:
材料科学
·
生物仿生学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Science
·
2024
·Vol. 11
·期 26
·2402824
·
IF 14.3
Chen Fei Dai,Qing Li Zhu,Olena Khoruzhenko,Michael Thelen,Huiying Bai,Josef Breu,Miao Du,Qiang Zheng,Zi Liang Wu
Creatures, such as Venus flytrap and hummingbirds, capable of rapid predation through snap-through transition, provide paradigms for the design of soft actuators and robots with fast actions. However, these artificial “snappers” usually need contact stimulations to trigger the flipping. Reported here is a constrained anisotropic poly( N -isopropylacrylamide) hydrogel showing fast snapping upon light stimulation. This hydrogel is prepared by flow-induced orientation of nanosheets (NSs) within a rectangular tube. The precursor containing gold nanoparticles is immediately exposed to UV light for photopolymerization to fix the ordered structure of NSs. Two ends of the slender gel are clamped to form a buckle with bistability nature, which snaps to the other side upon laser irradiation. Systematic experiments are conducted to investigate the influences of power intensity and irradiation angle of the laser, as well as thickness and buckle height of the gel, on the snapping behaviors. The fast snapping is further used to kick a plastic bead and control the switch state. Furthermore, synergetic or oscillated snapping of the gel with two buckles of opposite directions is realized by inclined irradiation of a laser or horizontal irradiation with two lasers, respectively. Such light-steered snapping of hydrogels should merit designing soft robots, energy harvests, etc.
研究领域:
软体机器人
·
材料科学
·
仿生学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 34
·2301982
·
IF 19
Qian Yan,Renjie Ding,Haowen Zheng,Pengyang Li,Zonglin Liu,Zhong Chen,Jinhua Xiong,Fuhua Xue,Xu Zhao,Qingyu Peng,Xiaodong He
Near-infrared (NIR) light-responsive hydrogels have the advantages of high precision, remote control and excellent biocompatibility, which are widely used in soft biomimetic actuators. The process by which water molecules diffuse can directly affect the deformation of hydrogel. Therefore, it remains a serious challenge to improve the response speed of hydrogel actuator. Herein, an anisotropic photo-responsive conductive hydrogel is designed by a directional freezing method. Due to the anisotropy of the MXene-based PNIPAM/MXene directional (PMD) hydrogel, its mechanical properties and conductivity are enhanced in a specific direction. At the same time, with the presence of the internal directional channels and the assistance of capillary force, the PMD hydrogel can achieve a volume deswelling of 70% in 2 s under light irradiation, further building a hydrogel actuator with a fast response performance. Additionally, the hydrogel actuator can lift an object 40 times its weight by a distance of 6 mm, realizing the advantages of both rapid responsiveness and high driving strength, which makes the hydrogel actuator have important application significance in remote control, microflow valve, and soft robot.
研究领域:
材料科学
·
生物医学工程
·
仿生学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2012
·
IF 2.307
Meiling Chen,Jintang Zhu,Guijin Qi,Changcheng He,Huiliang Wang
Biological gels are generally anisotropic in both structures and mechanical properties , but conventional synthetic hydrogels are generally isotropic. We developed a directional freezing and radiation-induced polymerization and crosslinking (DFRPC) method to fabricate anisotropic hydrogels starting from monomers. The obtained poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels show significant anisotropy in both microstructures and mechanical properties. The hydrogels exhibit an aligned porous structure along the freezing direction and an irregular porous structure in the vertical direction. Their elastic modulus and tensile stress in the parallel direction are significantly higher than those in the vertical direction, and the difference between the two directions decreases as the increase of HEMA concentration. This novel methodology offers a promising way to fabricate a wide variety of anisotropic hydrogels, and the anisotropic hydrogels may find practical applications in biomedical fields.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Mengtian Shang,Shaoshuai Ma,Jianfeng Ma,Luyao Guo,Cong Liu,Xinhua Xu
Intelligent stimulus-responsive actuation and excellent sensation of many living organisms have provided researchers a novel insight to fabricate biomimetic self-sensing systems. However, developing indispensable capabilities for somatosensory actuators with information on-demand display and storage encryption system remains a severe challenge. Herein, an intellective somatosensory gradient hydrogel actuator was demonstrated, which combined excellent actuating speed and high sensitivity for on-demand display and storage of information. The conductive hydrogels are synthesized by one-pot polymerization of poly(N-isopropylacrylamide) (namely PNIPAM) and polyaniline functionalized MXene (namely P-MXene) nanocomposites where P-MXene nanosheets offer photothermal responsive characteristics to hydrogel and generate directional migration under the DC electric field to make the hydrogel present anisotropic microstructure. The multifunctional hydrogels have advantages of fast response speed (9.23° s −1 ) and excellent cycle stability, augmented photothermal conversion efficiency (increase to 1.18 °C/s upon 808 nm near-infrared light), and the bending angle reached to 9° s −1 could be adjusted through light-driven remote control. Shape-programmable actuators are fabricated by devising ITO glass electrode patterns, controlling DC electric field direction, and thus various shape-morphing designs such as 6, U, S, Ω are watched under the NIR light irradiations, and the conductivity somatosensory hydrogel has outstanding strain sensor properties, within a universal strain range (100 %), good linearity (R 2 = 0.97) and high sensing properties (GF = 3.11). As a proof-of-concept, self-sensing actuators are applied for an information storage system and a simple deception for on-demand information display that can simultaneously deliver information via real-time displayed pattern variation. This work can provide fundamental research for smart soft actuators chemically integrating actuating speed and sensing functions in the field of information encryption.
研究领域:
材料科学
·
生物仿生学
·
智能系统
✓ 已验证
产品关联
DOI
高影响因子
Advanced Intelligent Systems
·
2021
·Vol. 3
·期 11
·2100030
·
IF 0
Pengli Dong,Weizhong Xu,Zhongwen Kuang,Youxing Yao,Zhiqin Zhang,Daoyou Guo,Huaping Wu,Tingyu Zhao,Aiping Liu
Smart hydrogel actuators with programmable anisotropic structures present fascinating prospects considering their distinctive shape transformation and controllable environmental responsiveness under external stimuli. However, the design of anisotropic hydrogels with simple and universal fabrication and programmable functionality is challenging for their valuable applications in smart actuators and soft robots. Herein, a simple, green, and devisable strategy is proposed to construct a heterogeneous porous hydrogel system by the different liquid diffusion (such as amyl alcohol, water, and ethanol) into a monomeric precursor solution of thermosensitive hydrogels. The well-defined micro/nanoporous gradient and patterned structures related to selective liquid stratification and interfacial diffusion favor the fast response and accurate programmable deformation of hydrogels under temperature stimuli. Inspiringly, this simple diffusion-driven tactic can be perfectly applicable for different responsive hydrogels with programmable multifunctionality by adding functional nanomaterials into the diffusible liquid. This green, general, and facile diffusion-driven strategy provides significant guidance for fabricating environmentally responsive hydrogels with tailorable functionality for their multipurpose applications in drug delivery, bioengineering, smart actuators, and soft robots.
研究领域:
材料科学
·
智能材料
·
软体机器人
✓ 已验证
产品关联
DOI
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Liangren Chen,Xiaohua Chang,Jianwen Chen,Yutian Zhu
Integrating structural anisotropy, excellent mechanical properties, and superior sensing capability into conductive hydrogels is of great importance to wearable flexible electronics yet challenging. Herein, inspired from the aligned structure of human muscle, we proposed a facile and universal method to construct an anisotropic hydrogel composed of polyacrylamide and sodium alginate by pre-stretching in a confined geometry and subsequent ionic cross-linking. The designed hydrogels showed extraordinary mechanical performances, such as ultrahigh stretchability, a comparable modulus to that of human tissues, and good toughness, ascribed to their anisotropically aligned polymer networks. Additionally, the hydrogel possessed anisotropic conductivity due to the anisotropy in ion transport channels. The hydrogel along the vertical direction was further cut and assembled into a flexible strain sensor, exhibiting a low detection limit (0.1%), wide strain range (1585%), rapid response (123 ms), distinct resilience, good stability, and repeatability, thereby being capable of monitoring and discriminating different human movements. In addition, the relatively high ionic conductivity and superior sensitivity enabled the anisotropic hydrogel sensor to be used for wireless human–machine interaction. More interestingly, the Ca2+-cross-linking strategy also endowed the hydrogel sensor with antifreezing ability, further broadening their working temperature. This work is expected to speed up the development of hydrogel sensors in the emerging wearable soft electronics.
研究领域:
材料科学
·
生物医学工程
·
柔性电子学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 7
·4099-4107
·
IF 10.7
Yuankun Wang,Defeng Wu
Sufficient water supply and evaporation interfaces are vital for hydrogels as solar evaporators, which require ingenious structural design, from the networks and porous structure inside the bulk to the surface morphology outside the hydrogel. A chitosan based anisotropic hydrogel with well-regulated surface architecture is reported here. The aligned channels formed inside the bulk via directional freezing ensure water supply, and the ionic crosslinking further improves the mechanical stability of the bulk and also reduces the evaporation enthalpy of the seawater inside the channels. The small vessels radially distributed over the pores of the evaporation surface, together with the large-sized pores, act as a reservoir, promoting salt exchange and water evaporation and on the other hand, as drains of concentrated seawater, favoring the accumulation of a salt shell outside the hydrogel. Thus, as-prepared solar evaporator shows desirable performance (3.86 kg m−2 h−1 evaporation rate and 96.7% conversion efficiency under 1 sun irradiation) and superior salt-collection ability. The evaporation rate can maintain well even after 10 desalination cycles (over 3.5 kg m−2 h−1, in 20% brine). This work gives an eco-friendly solution for clean water production by using chitosan-based hydrogel evaporators and proposes a method of regulating evaporation surface architecture for hydrogel-based evaporators.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 46
·51374
·
IF 3.125
Rongnian Xu,Xiaoduo Zhao,Shuanhong Ma,Zhengfeng Ma,Rui Wang,Meirong Cai,Feng Zhou
Anisotropic hydrogels are appealing with their merits of similar biochemical and structural properties to the biological tissues. However, the mechanical properties of current anisotropic hydrogels need to be further improved. Herein, three kinds of novel anisotropic poly(2-hydroxyethyl methacrylate) (pHEMA), poly(acrylamide) (pAM), and poly(acrylamide-co-acrylic acid) (p[AM-co-AA]) sugarcane composite hydrogels were prepared successfully by filling the hydrogel monomer precursor into porous aligned sugarcane nanofibers network and then performing subsequent free radical polymerization. The hydrogel matrix and sugarcane nanofibers network were combined closely together through hydrogen bonding interaction. The anisotropic sugarcane composite hydrogels exhibit good flexibility and elastic recovery properties upon encountering mechanical crimping and twisting. In typical case, the as-prepared pHEMA sugarcane composite hydrogel can exhibit high anisotropic tensile strength of 2.37 and 0.54 MPa, while differential tear strength of 0.36 and 0.78 N/mm, along the parallel and vertical nanofibers directions. Finally, anisotropic lubrication behaviors were found and investigated systematically for those three kinds of sugarcane composite hydrogels when water was used as lubricant. Our current work proposes a simple and universal strategy for developing bioinspired anisotropic functional composite matters such as artificial skin, flexible sensor, and cartilage lubrication materials.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Mulenga Kalulu,Onesmus Munyati,Olayinka Oderinde,Jun Hu,Shephrah O. Ogungbesan,Guodong Fu
Anisotropic hydrogel actuators with gradient structures offer tunable mechanical properties, like directional stiffness or bending. However, creating these gradient-structured bilayer hydrogels is challenging, as current methods rely on complex, single-force programming. Developing a double-actuating bilayer hydrogel with temperature-responsive and auxiliary layers could address these limitations and enhance their applicability. In this study, an anisotropic hydrogel actuator was developed using a simple, cost-effective method to create a unique multi-asymmetric structure with an embedded gradient in one layer. The resulting hydrogels exhibited excellent temperature-responsive bending (360° within 9 s) and adaptive, complex shape-programmable deformation (2D letters, flowers, butterflies, leaves). In addition, the hydrogels demonstrated good shape memory, mechanical strength, and conductivity. Prototypes of a hydrogel gripper and humidity alarm were successfully fabricated, showcasing the potential of this strategy for designing smart hydrogels for applications in sensors, smart humidity alarms, grippers, and actuators.
研究领域:
材料科学
·
智能材料
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shuang Chen,Bingyan Guo,Jiajun Yu,Zhuojun Yan,Rui Liu,Chaojie Yu,Zhongming Zhao,Hong Zhang,Fanglian Yao,Junjie Li
Flexible hydrogel-based wearable sensors are of interest for monitoring human movement and electrophysiological signal detection. The high mechanical properties, high conductivity, and sensing sensitivity are the main performance parameters. Inspired by the structure of human muscles, ligaments, and other tissues, a polypyrrole-dopamine/poly(vinyl alcohol) (DA-PPy/PVA) hydrogel with a bionic anisotropic structure is prepared in this study using a directed freeze–thaw strategy. The introduction of DA-PPy nanoparticles can significantly improve the mechanics, adhesion, and conductivity due to the high water dispersibility. Moreover, they can act as physical cross-linking sites to further improve the mechanical properties. The anisotropic structure would influence many properties (mechanical, conductivity, resistance to crack extension, etc.) of DA-PPy/PVA hydrogel. In addition, the prepared DA-PPy/PVA hydrogel exhibits a wide range of strain responses, moreover, its relative resistance change ( ΔR / R 0 ) strain curve maintains a line linear within 400% strain. The oriented structure would influence the sensing sensitivity, the gauge factor of anisotropic DA-PPy/PVA in parallel direction is 3.00. In addition, the anisotropic DA-PPy/PVA can effectively motor the physiological electrical signals as a bioelectrode. For example, the acquired electrocardiogram (ECG) and electromyography (EMG) signals not only are clearer than those of the commercial electrodes but show a higher signal-to-noise ratio. It is conceivable that the bionic anisotropic DA-PPy/PVA hydrogels provide a feasible material to construct flexible wearable sensors for monitoring human movement and electrophysiological signals.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Yuankun Wang,Jia Li,Nur Muhammad,Zhifeng Wang,Defeng Wu
Construction of hierarchical networks of anisotropic hydrogels has attracted much attention recently. We developed a simple strategy to fabricate anisotropic hydrogels with rich structural hierarchy and tunable mechanical properties by using the minor polymer as the performance and network regulators in this work. Poly(vinyl alcohol) (PVA)/poly(vinylpyrrolidone) (PVP) solution was used as precursor to build networks across multiple length scales via the directional freezing/salting-out treatments. The presence of PVP, as minor component, promoted the formation of the bridging fibers across the oriented channel-like pores. Thus, as-prepared two-component anisotropic hydrogels revealed superior mechanical strengths as compared to the two-component isotropic hydrogels or the single-component anisotropic ones. On the other hand, the formation of this dendritic structure improved the strength perpendicular to aligned direction, and therefore, the PVA/PVP anisotropic hydrogels possessed more balanced mechanical performance. In brief, PVP acted as the roles of network and performance regulators in this kind of anisotropic hydrogels. This work provides an interesting way to regulate morphology and overall properties of the PVA based anisotropic hydrogels.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）