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Li Y, Cheng Q, Deng Z, Zhang T, Luo M, Huang X, Wang Y, Wang W, Zhao X. Recent Progress of Anti-Freezing, Anti-Drying, and Anti-Swelling Conductive Hydrogels and Their Applications. Polymers (Basel) 2024; 16:971. [PMID: 38611229 PMCID: PMC11013939 DOI: 10.3390/polym16070971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Hydrogels are soft-wet materials with a hydrophilic three-dimensional network structure offering controllable stretchability, conductivity, and biocompatibility. However, traditional conductive hydrogels only operate in mild environments and exhibit poor environmental tolerance due to their high water content and hydrophilic network, which result in undesirable swelling, susceptibility to freezing at sub-zero temperatures, and structural dehydration through evaporation. The application range of conductive hydrogels is significantly restricted by these limitations. Therefore, developing environmentally tolerant conductive hydrogels (ETCHs) is crucial to increasing the application scope of these materials. In this review, we summarize recent strategies for designing multifunctional conductive hydrogels that possess anti-freezing, anti-drying, and anti-swelling properties. Furthermore, we briefly introduce some of the applications of ETCHs, including wearable sensors, bioelectrodes, soft robots, and wound dressings. The current development status of different types of ETCHs and their limitations are analyzed to further discuss future research directions and development prospects.
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Affiliation(s)
- Ying Li
- College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
| | - Qiwei Cheng
- College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
| | - Zexing Deng
- College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
| | - Tao Zhang
- College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
| | - Man Luo
- College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
| | - Xiaoxiao Huang
- College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
| | - Yuheng Wang
- Department of Radiology, Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Air Force Medical University, Xi’an 710038, China
| | - Wen Wang
- Department of Radiology, Functional and Molecular Imaging Key Lab of Shaanxi Province, Tangdu Hospital, Air Force Medical University, Xi’an 710038, China
| | - Xin Zhao
- State Key Laboratory for Mechanical Behavior of Materials, Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China
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Wang X, Wei W, Guo Z, Liu X, Liu J, Bing T, Yu Y, Yang X, Cai Q. Organic-inorganic composite hydrogels: compositions, properties, and applications in regenerative medicine. Biomater Sci 2024; 12:1079-1114. [PMID: 38240177 DOI: 10.1039/d3bm01766d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Hydrogels, formed from crosslinked hydrophilic macromolecules, provide a three-dimensional microenvironment that mimics the extracellular matrix. They served as scaffold materials in regenerative medicine with an ever-growing demand. However, hydrogels composed of only organic components may not fully meet the performance and functionalization requirements for various tissue defects. Composite hydrogels, containing inorganic components, have attracted tremendous attention due to their unique compositions and properties. Rigid inorganic particles, rods, fibers, etc., can form organic-inorganic composite hydrogels through physical interaction and chemical bonding with polymer chains, which can not only adjust strength and modulus, but also act as carriers of bioactive components, enhancing the properties and biological functions of the composite hydrogels. Notably, incorporating environmental or stimulus-responsive inorganic particles imparts smartness to hydrogels, hence providing a flexible diagnostic platform for in vitro cell culture and in vivo tissue regeneration. In this review, we discuss and compare a set of materials currently used for developing organic-inorganic composite hydrogels, including the modification strategies for organic and inorganic components and their unique contributions to regenerative medicine. Specific emphasis is placed on the interactions between the organic or inorganic components and the biological functions introduced by the inorganic components. The advantages of these composite hydrogels indicate their potential to offer adaptable and intelligent therapeutic solutions for diverse tissue repair demands within the realm of regenerative medicine.
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Affiliation(s)
- Xinyu Wang
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Wei Wei
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Ziyi Guo
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Xinru Liu
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Ju Liu
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Tiejun Bing
- Immunology and Oncology center, ICE Bioscience, Beijing 100176, China
| | - Yingjie Yu
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Xiaoping Yang
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
| | - Qing Cai
- State Key Laboratory of Organic-Inorganic Composites; Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China.
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Jurin FE, Buron CC, Frau E, del Rossi S, Schintke S. The Electrical and Mechanical Characteristics of Conductive PVA/PEDOT:PSS Hydrogel Foams for Soft Strain Sensors. SENSORS (BASEL, SWITZERLAND) 2024; 24:570. [PMID: 38257662 PMCID: PMC10819078 DOI: 10.3390/s24020570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/22/2023] [Accepted: 01/12/2024] [Indexed: 01/24/2024]
Abstract
Conductive hydrogels are of interest for highly flexible sensor elements. We compare conductive hydrogels and hydrogel foams in view of strain-sensing applications. Polyvinyl alcool (PVA) and poly(3,4-ethylenedioxythiophene (PEDOT:PSS) are used for the formulation of conductive hydrogels. For hydrogel foaming, we have investigated the influence of dodecylbenzenesulfonate (DBSA) as foaming agent, as well as the influence of air incorporation at various mixing speeds. We showed that DBSA acting as a surfactant, already at a concentration of 1.12wt%, efficiently stabilizes air bubbles, allowing for the formulation of conductive PVA and PVA/PEDOT:PSS hydrogel foams with low density (<400 kg/m3) and high water uptake capacity (swelling ratio > 1500%). The resulting Young moduli depend on the air-bubble incorporation from mixing, and are affected by freeze-drying/rehydration. Using dielectric broadband spectroscopy under mechanical load, we demonstrate that PVA/PEDOT:PSS hydrogel foams exhibit a significant decrease in conductivity under mechanical compression, compared to dense hydrogels. The frequency-dependent conductivity of the hydrogels exhibits two plateaus, one in the low frequency range, and one in the high frequency range. We find that the conductivity of the PVA/PEDOT:PSS hydrogels decreases linearly as a function of pressure in each of the frequency regions, which makes the hydrogel foams highly interesting in view of compressive strain-sensing applications.
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Affiliation(s)
- Florian E. Jurin
- Institut UTINAM, UMR 6213 CNRS-UBFC, Université de Bourgogne Franche-Comté (UBFC), F-25030 Besançon Cedex, France;
| | - Cédric C. Buron
- Institut UTINAM, UMR 6213 CNRS-UBFC, Université de Bourgogne Franche-Comté (UBFC), F-25030 Besançon Cedex, France;
| | - Eleonora Frau
- Laboratory of Applied NanoSciences (COMATEC-LANS), University of Applied Sciences Western Switzerland (HES-SO), CH-1401 Yverdon-les-Bains, Switzerland
| | - Stefan del Rossi
- Laboratory of Applied NanoSciences (COMATEC-LANS), University of Applied Sciences Western Switzerland (HES-SO), CH-1401 Yverdon-les-Bains, Switzerland
| | - Silvia Schintke
- Laboratory of Applied NanoSciences (COMATEC-LANS), University of Applied Sciences Western Switzerland (HES-SO), CH-1401 Yverdon-les-Bains, Switzerland
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Yan Y, Shi Y, Liu C, Shao J, Sun N, Ma B, Li Y, Huang J, Ge S. Cartilage-Inspired Inhomogeneous Salt-Hydrogel for Hydrated Drag-Reducing and Strain Sensing. ACS APPLIED MATERIALS & INTERFACES 2023; 15:48632-48644. [PMID: 37788004 DOI: 10.1021/acsami.3c10271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Articular cartilages exhibit load-bearing capacity and durability due to their inhomogeneous structure. Inspired by this unique structure, a tough and inhomogeneous salt-hydrogel was developed by trapping sodium acetate (NaAc) crystals in polyacrylamide (PAM) polymer networks and then partially redissolving the NaAc crystals. The compressive and tensile stresses of the salt-hydrogel increase significantly by more than 20 times when oversaturated Ac- and Na+ are introduced into the gel network. Such an enhancement in mechanical strength is primarily attributed to the formation of NaAc crystals within the gel network. Further investigations reveal that the mechanical strength of the salt-hydrogel is temperature-dependent as the NaAc crystals gradually redissolve in the gel network with increasing temperature. Furthermore, redissolving NaAc crystals in an aqueous solution can yield an inhomogeneous salt-hydrogel. The topmost soft surface of the salt-hydrogel offers hydration lubrication, while the inhomogeneous network confers load-bearing capacity and durability. Compared to regular hydrogels, the inhomogeneous salt-hydrogel surface can realize drag reduction and remain smooth without damage after the friction tests. Moreover, a salt-hydrogel coating is also fabricated to visually demonstrate its drag-reducing property. In addition, this salt-hydrogel possesses conductivity and can be utilized in the development of inhomogeneous salt-hydrogel fibers (diameter = 438 ± 7 μm) for strain detection. The produced salt-hydrogel fiber exhibits excellent durability and reproducibility as a strain sensor, capable of detecting both small strains (e.g., 1%) and large strains (e.g., 40%). This work provides fundamental insights into developing hydrogels with an inhomogeneous network and explores their potential applications (e.g., hydrated drag-reducing, strain sensing).
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Affiliation(s)
- Yonggan Yan
- Department of Periodontology & Tissue Engineering and Regeneration, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Shandong University, Jinan 250012, China
| | - Yanping Shi
- Shandong Institute of Medical Device and Pharmaceutical Packaging Inspection, NMPA Key Laboratory for Safety Evaluation of Biomaterials and Medical Devices, Jinan 250101, China
| | - Chenghu Liu
- Shandong Institute of Medical Device and Pharmaceutical Packaging Inspection, NMPA Key Laboratory for Safety Evaluation of Biomaterials and Medical Devices, Jinan 250101, China
| | - Jinlong Shao
- Department of Periodontology & Tissue Engineering and Regeneration, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Shandong University, Jinan 250012, China
| | - Nengzhe Sun
- Department of Periodontology & Tissue Engineering and Regeneration, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Shandong University, Jinan 250012, China
| | - Baojin Ma
- Department of Periodontology & Tissue Engineering and Regeneration, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Shandong University, Jinan 250012, China
| | - Yuan Li
- Sinopec Research Institute of Petroleum Engineering, Fracturing & Acidizing and Natural Gas Production Research Institute, Dongying 257000, China
| | - Jun Huang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, Shandong, China
| | - Shaohua Ge
- Department of Periodontology & Tissue Engineering and Regeneration, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Shandong University, Jinan 250012, China
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5
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Ding H, Liu J, Shen X, Li H. Advances in the Preparation of Tough Conductive Hydrogels for Flexible Sensors. Polymers (Basel) 2023; 15:4001. [PMID: 37836050 PMCID: PMC10575238 DOI: 10.3390/polym15194001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/24/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023] Open
Abstract
The rapid development of tough conductive hydrogels has led to considerable progress in the fields of tissue engineering, soft robots, flexible electronics, etc. Compared to other kinds of traditional sensing materials, tough conductive hydrogels have advantages in flexibility, stretchability and biocompatibility due to their biological structures. Numerous hydrogel flexible sensors have been developed based on specific demands for practical applications. This review focuses on tough conductive hydrogels for flexible sensors. Representative tactics to construct tough hydrogels and strategies to fulfill conductivity, which are of significance to fabricating tough conductive hydrogels, are briefly reviewed. Then, diverse tough conductive hydrogels are presented and discussed. Additionally, recent advancements in flexible sensors assembled with different tough conductive hydrogels as well as various designed structures and their sensing performances are demonstrated in detail. Applications, including the wearable skins, bionic muscles and robotic systems of these hydrogel-based flexible sensors with resistive and capacitive modes are discussed. Some perspectives on tough conductive hydrogels for flexible sensors are also stated at the end. This review will provide a comprehensive understanding of tough conductive hydrogels and will offer clues to researchers who have interests in pursuing flexible sensors.
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Affiliation(s)
- Hongyao Ding
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China; (H.D.)
| | - Jie Liu
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China; (H.D.)
| | - Xiaodong Shen
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009, China; (H.D.)
| | - Hui Li
- Key Laboratory for Light-Weight Materials, Nanjing Tech University, Nanjing 210009, China
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Jiang L, Tian S, Xie Y, Lv X, Sun S. High Strength, Conductivity, and Bacteriostasis of the P(AM- co-AA)/Chitosan Quaternary Ammonium Salt Composite Hydrogel through Ionic Crosslinking and Hydrogen Bonding. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37314954 DOI: 10.1021/acs.langmuir.3c00646] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Traditional hydrogels with a single-crosslinked network structure suffer from poor stretchability, low sensitivity, and easy contamination, which seriously affect their practical application in the strain sensor field. To overcome these shortcomings, herein, a multiphysical crosslinking strategy (ionic crosslinking and hydrogen bonding) was designed to prepare a hydrogel strain sensor based on chitosan quaternary ammonium salt (HACC)-modified P(AM-co-AA) (acrylamide-co-acrylic acid copolymer) hydrogels. The ionic crosslinking for the double-network P(AM-co-AA)/HACC hydrogels was achieved by an immersion method with Fe3+ as crosslinking sites, which crosslinked with the amino group (-NH2) on HACC and the carboxyl group (-COOH) on P(AM-co-AA) and enabled the hydrogels to recover and reorganize rapidly, resulting in a hydrogel-based strain sensor with excellent tensile stress (3 MPa), elongation (1390%), elastic modulus (0.42 MPa), and toughness (25 MJ/m3). In addition, the prepared hydrogel exhibited high electrical conductivity (21.6 mS/cm) and sensitivity (GF = 5.02 at 0-20% strain, GF = 6.84 at 20-100% strain, and GF = 10.27 at 100-480% strain). Furthermore, the introduction of HACC endowed the hydrogel with excellent antibacterial properties (up to 99.5%) and excellent antibacterial activity against bacteria of three forms, bacilli, cocci, and spores. The flexible, conductive, and antibacterial hydrogel can be applied as a strain sensor for real-time detection of human motions such as joint movement, speech, and respiration, which exhibits a promising application prospect in wearable devices, soft robotic systems, and other fields.
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Affiliation(s)
- Li'an Jiang
- School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun 130012, China
| | - Song Tian
- School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun 130012, China
| | - Yuhui Xie
- School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun 130012, China
| | - Xue Lv
- School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun 130012, China
| | - Shulin Sun
- School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun 130012, China
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Muhammad W, Kim SD. Highly Stretchable PPy/PDMS Strain Sensors Fabricated with Multi-Step Oxygen Plasma Treatment. Polymers (Basel) 2023; 15:polym15071714. [PMID: 37050328 PMCID: PMC10096996 DOI: 10.3390/polym15071714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/27/2023] [Accepted: 03/27/2023] [Indexed: 04/14/2023] Open
Abstract
We present highly stretchable polypyrrole (PPy)/polydimethylsiloxane strain sensors of highly improved sensitivity and durability fabricated by a chemical oxidative polymerization with oxygen plasma treatment (O2 PT). In this study, O2 PT was performed for 30, 60, and 90 s at each growth stage of the PPy film in three steps to investigate the effects on the sensor performance as well as the microstructural properties of the PPy films. Bonding characteristics with underlying layers and resistance to microcrack generation of the multi-layer PPy films under our given strained state were significantly enhanced by the O2 PT. The best sensor performance in terms of sensitivity and stability were achieved by PT for 30 s with a maximum gauge factor of ~438 at a uniaxial strain of 50%, excellent durability over 500 stretching/release cycles, and a fast response time of ~50 ms.
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Affiliation(s)
- Waqar Muhammad
- Division of Electronics and Electrical Engineering, Dongguk University, Seoul 100-175, Republic of Korea
| | - Sam-Dong Kim
- Division of Electronics and Electrical Engineering, Dongguk University, Seoul 100-175, Republic of Korea
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8
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Liang Q, Shen Z, Sun X, Yu D, Liu K, Mugo SM, Chen W, Wang D, Zhang Q. Electron Conductive and Transparent Hydrogels for Recording Brain Neural Signals and Neuromodulation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211159. [PMID: 36563409 DOI: 10.1002/adma.202211159] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Recording brain neural signals and optogenetic neuromodulations open frontiers in decoding brain neural information and neurodegenerative disease therapeutics. Conventional implantable probes suffer from modulus mismatch with biological tissues and an irreconcilable tradeoff between transparency and electron conductivity. Herein, a strategy is proposed to address these tradeoffs, which generates conductive and transparent hydrogels with polypyrrole-decorated microgels as cross-linkers. The optical transparency of the electrodes can be attributed to the special structures that allow light waves to bypass the microgel particles and minimize their interaction. Demonstrated by probing the hippocampus of rat brains, the biomimetic electrode shows a prolonged capacity for simultaneous optogenetic neuromodulation and recording of brain neural signals. More importantly, an intriguing brain-machine interaction is realized, which involves signal input to the brain, brain neural signal generation, and controlling limb behaviors. This breakthrough work represents a significant scientific advancement toward decoding brain neural information and developing neurodegenerative disease therapies.
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Affiliation(s)
- Quanduo Liang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Zhenzhen Shen
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Xiguang Sun
- Department of Hand Surgery, Public Research Platform, The First Hospital of Jilin University, Changchun, 130061, P. R. China
| | - Dehai Yu
- Department of Hand Surgery, Public Research Platform, The First Hospital of Jilin University, Changchun, 130061, P. R. China
| | - Kewei Liu
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, P. R. China
| | - Samuel M Mugo
- Department of Physical Sciences, MacEwan University, Edmonton, ABT5J4S2, Canada
| | - Wei Chen
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Dong Wang
- Key Laboratory of Biomedical Engineering of Hainan Province, School of Biomedical Engineering, Hainan University, Haikou, 570228, China
| | - Qiang Zhang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
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Yu JY, Moon SE, Kim JH, Kang SM. Ultrasensitive and Highly Stretchable Multiple-Crosslinked Ionic Hydrogel Sensors with Long-Term Stability. NANO-MICRO LETTERS 2023; 15:51. [PMID: 36790572 PMCID: PMC9931967 DOI: 10.1007/s40820-023-01015-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/26/2022] [Indexed: 06/18/2023]
Abstract
Flexible hydrogels are receiving significant attention for their application in wearable sensors. However, most hydrogel materials exhibit weak and one-time adhesion, low sensitivity, ice crystallization, water evaporation, and poor self-recovery, thereby limiting their application as sensors. These issues are only partly addressed in previous studies. Herein, a multiple-crosslinked poly(2-(methacryloyloxy)ethyl)dimethyl-(3-sulfopropyl)ammonium hydroxide-co-acrylamide) (P(SBMA-co-AAm)) multifunctional hydrogel is prepared via a one-pot synthesis method to overcome the aforementioned limitations. Specifically, ions, glycerol, and 2-(methacryloyloxy)ethyl)dimethyl-(3-sulfopropyl)ammonium hydroxide are incorporated to reduce the freezing point and improve the moisture retention ability. The proposed hydrogel is superior to existing hydrogels because it exhibits good stretchability (a strain of 2900%), self-healing properties, and transparency through effective energy dissipation in its dynamic crosslinked network. Further, 2-(methacryloyloxy)ethyl)dimethyl-(3-sulfopropyl)ammonium hydroxide as a zwitterion monomer results in an excellent gauge factor of 43.4 at strains of 1300-1600% by improving the ion transportability and achieving a strong adhesion of 20.9 kPa owing to the dipole-dipole moment. The proposed hydrogel is promising for next-generation biomedical applications, such as soft robots, and health monitoring.
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Affiliation(s)
- Jin-Young Yu
- Department of Mechanical Engineering, Chungnam National University, Daejeon, 34134, Korea
| | - Seung Eon Moon
- Emerging Nano-Materials Research Section, Electronics and Telecommunications Research Institute, Daejeon, 305-700, Republic of Korea
| | - Jeong Hun Kim
- Emerging Nano-Materials Research Section, Electronics and Telecommunications Research Institute, Daejeon, 305-700, Republic of Korea.
| | - Seong Min Kang
- Department of Mechanical Engineering, Chungnam National University, Daejeon, 34134, Korea.
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10
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Lai QT, Sun QJ, Tang Z, Tang XG, Zhao XH. Conjugated Polymer-Based Nanocomposites for Pressure Sensors. Molecules 2023; 28:1627. [PMID: 36838615 PMCID: PMC9964060 DOI: 10.3390/molecules28041627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Flexible sensors are the essential foundations of pressure sensing, microcomputer sensing systems, and wearable devices. The flexible tactile sensor can sense stimuli by converting external forces into electrical signals. The electrical signals are transmitted to a computer processing system for analysis, realizing real-time health monitoring and human motion detection. According to the working mechanism, tactile sensors are mainly divided into four types-piezoresistive, capacitive, piezoelectric, and triboelectric tactile sensors. Conventional silicon-based tactile sensors are often inadequate for flexible electronics due to their limited mechanical flexibility. In comparison, polymeric nanocomposites are flexible and stretchable, which makes them excellent candidates for flexible and wearable tactile sensors. Among the promising polymers, conjugated polymers (CPs), due to their unique chemical structures and electronic properties that contribute to their high electrical and mechanical conductivity, show great potential for flexible sensors and wearable devices. In this paper, we first introduce the parameters of pressure sensors. Then, we describe the operating principles of resistive, capacitive, piezoelectric, and triboelectric sensors, and review the pressure sensors based on conjugated polymer nanocomposites that were reported in recent years. After that, we introduce the performance characteristics of flexible sensors, regarding their applications in healthcare, human motion monitoring, electronic skin, wearable devices, and artificial intelligence. In addition, we summarize and compare the performances of conjugated polymer nanocomposite-based pressure sensors that were reported in recent years. Finally, we summarize the challenges and future directions of conjugated polymer nanocomposite-based sensors.
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Affiliation(s)
- Qin-Teng Lai
- School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou 511400, China
| | - Qi-Jun Sun
- School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou 511400, China
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 518060, China
| | - Zhenhua Tang
- School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou 511400, China
| | - Xin-Gui Tang
- School of Physics and Optoelectric Engineering, Guangdong University of Technology, Guangzhou 511400, China
| | - Xin-Hua Zhao
- Department of Chemistry, South University of Science and Technology of China, Shenzhen 518060, China
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11
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Shi G, Zhan T, Hu Y, Guo Z, Wang S. A stretchable, self-adhesive, conductive double-network hydrogel and its application in flexible strain sensors. JOURNAL OF POLYMER RESEARCH 2023. [DOI: 10.1007/s10965-023-03441-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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12
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Liu Q, Wang X, Hou Y, Cheng Y, Zhang J, Xiao L, Zhao J, Li W. Bio-inspired Hydrogel Actuator with Rapid Self-strengthening Behavior. Eur Polym J 2023. [DOI: 10.1016/j.eurpolymj.2023.111941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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13
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Xie Y, Lv X, Li Y, Lv A, Sui X, Tian S, Jiang L, Li R, Sun S. Carbon Nanotubes and Silica@polyaniline Core-Shell Particles Synergistically Enhance the Toughness and Electrical Conductivity in Hydrophobic Associated Hydrogels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:1299-1308. [PMID: 36630713 DOI: 10.1021/acs.langmuir.2c03128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Soft, conductive, and stretchable sensors are highly desirable in many applications, including artificial skin, biomonitoring patches, and so on. Recently, a combination of good electrical and mechanical properties was regarded as the most important evaluation criterion for judging whether hydrogel sensors are suitable for practical applications. Herein, we demonstrate a novel carboxylated carbon nanotube (MWCNT-COOH)-embedded P(AM/LMA)/SiO2@PANI hydrogel. The hydrogel benefits from a double-network structure (hydrogen bond cross-linking and hydrophobic connectivity network) due to the role of MWCNT-COOH and SiO2@PANI as cross-linkers, thus resulting in tough composite hydrogels. The obtained P(AM/LMA)/SiO2@PANI/MWCNT-COOH hydrogels exhibited high tensile strength (1939 kPa), super stretchability (3948.37%), and excellent strain sensitivity (gauge factor = 11.566 at 100-1100% strain). Obviously, MWCNT-COOH not only improved the electrical conductivity but also enhanced the mechanical properties of the hydrogel. Therefore, the integration of MWCNT-COOH and SiO2@PANI-based hydrogel strain sensors will display broad application in sophisticated intelligence, soft robotics, bionic prosthetics, personal health care, and other fields using inexpensive, green, and easily available biomass.
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Affiliation(s)
- Yuhui Xie
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Xue Lv
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Youqiang Li
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Aowei Lv
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Xinyi Sui
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Song Tian
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Li'an Jiang
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Ruifeng Li
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
| | - Shulin Sun
- School of Chemical Engineering, Changchun University of Technology, Changchun130012, China
- Engineering Research Center of Synthetic Resin and Special Fiber, Ministry of Education, Changchun University of Technology, Changchun130012, China
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14
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Wang H, Li X, Ji Y, Xu J, Ye Z, Wang S, Du X. Highly transparent, mechanical, and self-adhesive zwitterionic conductive hydrogels with polyurethane as a cross-linker for wireless strain sensors. J Mater Chem B 2022; 10:2933-2943. [PMID: 35302157 DOI: 10.1039/d2tb00157h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Zwitterionic hydrogels have attracted a myriad of research interests for their excellent flexibility and biocompatibility as flexible wearable sensors. It is desired to create E-skins that integrate high mechanical strength, sensory sensitivity, and broad adhesion, possessing potential in the fields of intelligent robots and bionic prostheses. In this work, a novel macromolecular cross-linker (MPU) based on waterborne polyurethane (WPU) was designed and applied to synthesize multifunctional conductive hydrogels (PASU-Zn hydrogels). Importantly, in the presence of MPU, the hydrogels exhibited well-balanced mechanical properties (elongation at break 1193%, tensile strength 1.02 MPa, outstanding puncture resistance, and self-recovery abilities). When assembled as wireless strain sensors, PASU-Zn sensors displayed distinguished sensing characteristics to detect mechanotransduction signals of human movements in real-time. Specifically, owing to the dipole-dipole interaction and hydrogen bonding of zwitterions and MPU, the hydrogels have remarkable self-adhesion properties to various surfaces of wood, PDMS, and pigskin, allowing them to stick to skins by themselves without using any adhesive tapes when used. It is deemed that the as-designed zwitterionic hydrogels show great promise for wearable devices and bionic skins.
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Affiliation(s)
- Haibo Wang
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China. .,The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, P. R. China
| | - Xiaoyi Li
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
| | - Ying Ji
- Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Junhuai Xu
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
| | - Zhifan Ye
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
| | - Shuang Wang
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
| | - Xiaosheng Du
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
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15
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Peng X, Wang W, Yang W, Chen J, Peng Q, Wang T, Yang D, Wang J, Zhang H, Zeng H. Stretchable, compressible, and conductive hydrogel for sensitive wearable soft sensors. J Colloid Interface Sci 2022; 618:111-120. [PMID: 35338921 DOI: 10.1016/j.jcis.2022.03.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/01/2022] [Accepted: 03/08/2022] [Indexed: 02/06/2023]
Abstract
Conductive hydrogels hold great promises in wearable soft electronics. However, the weak mechanical properties, low sensitivity and the absence of multifunctionalities (e.g., self-healing, self-adhesive, etc.) of the conventional conductive hydrogels limit their applications. Thus, developing multifunctional hydrogels may address some of these technical issues. In this work, a multifunctional conductive hydrogel strain sensor is fabricated by incorporating a conductive polymer Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT: PSS) into a mechanically robust poly (vinyl alcohol) (PVA)/ poly (acrylic acid) (PAA) double network (DN) hydrogel. The as-prepared hydrogel sensor could span a wide spectrum of mechanical properties by simply tuning the polymer composition and the number of freezing-thawing cycles. In addition, the dynamic hydrogen bonding interactions endow the hydrogel sensor with self-healing property and reversible adhesiveness on diverse substrates. Moreover, the hydrogel sensor shows high sensitivity (Gauge Factor from 2.21 to 3.82) and can precisely detect some subtle human motions (e.g., pulse and vocal cord vibration). This work provides useful insights into the development of conductive hydrogel-based wearable soft electronics.
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Affiliation(s)
- Xuwen Peng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Wenda Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Wenshuai Yang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Jingsi Chen
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Qiongyao Peng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Tao Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Diling Yang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Jianmei Wang
- Heavy Machinery Engineering Research Center of Education Ministry, Taiyuan University of Science and Technology, Taiyuan 030024, China
| | - Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
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Li G, Li C, Li G, Yu D, Song Z, Wang H, Liu X, Liu H, Liu W. Development of Conductive Hydrogels for Fabricating Flexible Strain Sensors. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2101518. [PMID: 34658130 DOI: 10.1002/smll.202101518] [Citation(s) in RCA: 101] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 08/07/2021] [Indexed: 06/13/2023]
Abstract
Conductive hydrogels can be prepared by incorporating various conductive materials into polymeric network hydrogels. In recent years, conductive hydrogels have been developed and applied in the field of strain sensors owing to their unique properties, such as electrical conductivity, mechanical properties, self-healing, and anti-freezing properties. These remarkable properties allow conductive hydrogel-based strain sensors to show excellent performance for identifying external stimuli and detecting human body movement, even at subzero temperatures. This review summarizes the properties of conductive hydrogels and their application in the fabrication of strain sensors working in different modes. Finally, a brief prospectus for the development of conductive hydrogels in the future is provided.
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Affiliation(s)
- Gang Li
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Chenglong Li
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Guodong Li
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Dehai Yu
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Zhaoping Song
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Huili Wang
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Xiaona Liu
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
| | - Hong Liu
- Institute for Advanced Interdisciplinary Research, University of Jinan (iAIR), Jinan, 250022, China
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P. R. China
| | - Wenxia Liu
- State Key Laboratory of Biobased Materials and Green Papermaking, Qilu University of Technology, Shandong Academy of Science, Jinan, Shandong, 250353, China
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Xie F, Gao X, Yu Y, Lu F, Zheng L. Dually cross-linked single network poly(ionic liquid)/ionic liquid ionogels for a flexible strain-humidity bimodal sensor. SOFT MATTER 2021; 17:10918-10925. [PMID: 34811559 DOI: 10.1039/d1sm01453f] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Gel electrolytes have aroused extensive interest for diverse flexible electronics due to their high ionic conductivity and inherent stretchability. However, gel electrolytes still face challenges in terms of mechanical properties, fatigue resistance, and environmental adaptation, which severely limit the practical application of gel-based electronics. In this paper, we have synthesized a novel polymerizable ionic liquid [SBMA][AA] by mixing zwitterionic sulfobetaine methacrylate with acrylic acid. Then a dually cross-linked single network poly(ionic liquid)/ionic liquid (DCSN PIL/IL) ionogel was prepared by a simple one-step photopolymerization of the [SBMA][AA] in another IL 1-ethyl-3-methylimidazolium dicyanoamide ([EmIm][DCA]). The synergistic effect between covalent crosslinking and dynamic physical crosslinking points endows the ionogel with good mechanical properties as well as outstanding fatigue resistance. Gratifyingly, the entrapment of [EmIm][DCA] in the ionogel matrix yields excellent environmental adaptability and high ionic conductivity. Meanwhile, the DCSN PIL/IL ionogel also exhibited strong adhesive capacity due to the abundance of carboxyl and sulphonic acid groups. The outstanding electromechanical properties make the DCSN PIL/IL ionogel a perfect candidate for strain sensors to monitor diverse human body activities, such as the movement of the thumb knuckle and handwriting. Interestingly, the DCSN PIL/IL ionogel also displayed high responsiveness to humidity. Therefore, it is believed that this DCSN PIL/IL ionogel offers a broad prospect in flexible strain-humidity bimodal sensors.
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Affiliation(s)
- Fengjin Xie
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China.
| | - Xinpei Gao
- Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, No 58, Renmin Avenue, Haikou 570228, China.
| | - Yang Yu
- School of Chemistry and Chemical Engineering, Qilu Normal University, Jinan 250200, China
| | - Fei Lu
- Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, Hainan University, No 58, Renmin Avenue, Haikou 570228, China.
| | - Liqiang Zheng
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China.
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Veeramuthu L, Venkatesan M, Benas JS, Cho CJ, Lee CC, Lieu FK, Lin JH, Lee RH, Kuo CC. Recent Progress in Conducting Polymer Composite/Nanofiber-Based Strain and Pressure Sensors. Polymers (Basel) 2021; 13:4281. [PMID: 34960831 PMCID: PMC8705576 DOI: 10.3390/polym13244281] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 01/11/2023] Open
Abstract
The Conducting of polymers belongs to the class of polymers exhibiting excellence in electrical performances because of their intrinsic delocalized π- electrons and their tunability ranges from semi-conductive to metallic conductive regime. Conducting polymers and their composites serve greater functionality in the application of strain and pressure sensors, especially in yielding a better figure of merits, such as improved sensitivity, sensing range, durability, and mechanical robustness. The electrospinning process allows the formation of micro to nano-dimensional fibers with solution-processing attributes and offers an exciting aspect ratio by forming ultra-long fibrous structures. This review comprehensively covers the fundamentals of conducting polymers, sensor fabrication, working modes, and recent trends in achieving the sensitivity, wide-sensing range, reduced hysteresis, and durability of thin film, porous, and nanofibrous sensors. Furthermore, nanofiber and textile-based sensory device importance and its growth towards futuristic wearable electronics in a technological era was systematically reviewed to overcome the existing challenges.
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Affiliation(s)
- Loganathan Veeramuthu
- Institute of Organic and Polymeric Materials, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan; (L.V.); (M.V.); (J.-S.B.)
| | - Manikandan Venkatesan
- Institute of Organic and Polymeric Materials, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan; (L.V.); (M.V.); (J.-S.B.)
| | - Jean-Sebastien Benas
- Institute of Organic and Polymeric Materials, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan; (L.V.); (M.V.); (J.-S.B.)
| | - Chia-Jung Cho
- Institute of Organic and Polymeric Materials, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan; (L.V.); (M.V.); (J.-S.B.)
| | - Chia-Chin Lee
- Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei 11220, Taiwan;
| | - Fu-Kong Lieu
- Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei 11220, Taiwan;
- Department of Physical Medicine and Rehabilitation, National Defense Medical Center, Taipei 11490, Taiwan
| | - Ja-Hon Lin
- Institute of Electro-Optical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan;
| | - Rong-Ho Lee
- Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan;
| | - Chi-Ching Kuo
- Institute of Organic and Polymeric Materials, Research and Development Center of Smart Textile Technology, National Taipei University of Technology, Taipei 10608, Taiwan; (L.V.); (M.V.); (J.-S.B.)
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19
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Zhang J, Wang Y, Wei Q, Wang Y, Lei M, Li M, Li D, Zhang L, Wu Y. Self-Healing Mechanism and Conductivity of the Hydrogel Flexible Sensors: A Review. Gels 2021; 7:216. [PMID: 34842713 PMCID: PMC8628684 DOI: 10.3390/gels7040216] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 12/19/2022] Open
Abstract
Sensors are devices that can capture changes in environmental parameters and convert them into electrical signals to output, which are widely used in all aspects of life. Flexible sensors, sensors made of flexible materials, not only overcome the limitations of the environment on detection devices but also expand the application of sensors in human health and biomedicine. Conductivity and flexibility are the most important parameters for flexible sensors, and hydrogels are currently considered to be an ideal matrix material due to their excellent flexibility and biocompatibility. In particular, compared with flexible sensors based on elastomers with a high modulus, the hydrogel sensor has better stretchability and can be tightly attached to the surface of objects. However, for hydrogel sensors, a poor mechanical lifetime is always an issue. To address this challenge, a self-healing hydrogel has been proposed. Currently, a large number of studies on the self-healing property have been performed, and numerous exciting results have been obtained, but there are few detailed reviews focusing on the self-healing mechanism and conductivity of hydrogel flexible sensors. This paper presents an overview of self-healing hydrogel flexible sensors, focusing on their self-healing mechanism and conductivity. Moreover, the advantages and disadvantages of different types of sensors have been summarized and discussed. Finally, the key issues and challenges for self-healing flexible sensors are also identified and discussed along with recommendations for the future.
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Affiliation(s)
- Juan Zhang
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Yanen Wang
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Qinghua Wei
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Yanmei Wang
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Mingju Lei
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Mingyang Li
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Dinghao Li
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Longyu Zhang
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
| | - Yu Wu
- Industry Engineering Department, School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China; (J.Z.); (Y.W.); (M.L.); (M.L.); (D.L.); (L.Z.); (Y.W.)
- Institute of Medical Research, Northwestern Polytechnical University, Xi’an 710072, China
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Chen CK, Chen PW, Wang HJ, Yeh MY. Alkyl Chain Length Effects of Imidazolium Ionic Liquids on Electrical and Mechanical Performances of Polyacrylamide/Alginate-Based Hydrogels. Gels 2021; 7:164. [PMID: 34698178 PMCID: PMC8544473 DOI: 10.3390/gels7040164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/23/2021] [Accepted: 10/01/2021] [Indexed: 12/11/2022] Open
Abstract
Conductive hydrogels with stretchable, flexible and wearable properties have made significant contributions in the area of modern electronics. The polyacrylamide/alginate hydrogels are one of the potential emerging materials for application in a diverse range of fields because of their high stretch and toughness. However, most researchers focus on the investigation of their mechanical and swelling behaviors, and the adhesion and effects of the ionic liquids on the conductivities of polyacrylamide/alginate hydrogels are much less explored. Herein, methacrylated lysine and different alkyl chain substituted imidazole-based monomers (IMCx, x = 2, 4, 6 and 8) were introduced to prepare a series of novel pAMAL-IMCx-Ca hydrogels. We systematically investigated their macroscopic and microscopic properties through tensile tests, electrochemical impedance spectra and scanning electron microscopy, as well as Fourier transform infrared spectroscopy, and demonstrated that an alkyl chain length of the IMCx plays an important role in the designing of hydrogel strain sensors. The experiment result shows that the hexyl chains of IMC6 can effectively entangle with LysMA through hydrophobic and electrostatic interactions, which significantly enhance the mechanical strength of the hydrogels. Furthermore, the different strain rates and the durability of the pAMAL-IMC6-Ca hydrogel were investigated and the relative resistance responses remain almost the same in both conditions, making it a potential candidate for wearable strain sensors.
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Affiliation(s)
- Chen-Kang Chen
- Department of Chemistry, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan; (C.-K.C.); (P.-W.C.); (H.-J.W.)
| | - Po-Wen Chen
- Department of Chemistry, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan; (C.-K.C.); (P.-W.C.); (H.-J.W.)
| | - Huan-Jung Wang
- Department of Chemistry, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan; (C.-K.C.); (P.-W.C.); (H.-J.W.)
| | - Mei-Yu Yeh
- Department of Chemistry, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan; (C.-K.C.); (P.-W.C.); (H.-J.W.)
- Center for Nano Technology, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan
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