Research progress on IPMC's material compositions and actuation/sensing properties
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摘要: 离子交换聚合物/金属复合材料(IPMC)可作为柔性的驱动器与传感器,用于仿生机械、医疗器械等领域。驱动器是IPMC的主要应用,存在输出功率低、驱动不稳定等问题。传感器是IPMC的重要应用,存在感应电压低、干扰大等缺陷。优化电极、电解质膜、电解质溶液的材料组成有望解决上述问题。驱动器方面,本文梳理了不同聚合物电解质膜的改性技术及驱动特点,重点归纳了电解质膜的成分、结构制约其物理性能(如离子交换当量、含水量、力学性能),进而制约其驱动性能(如位移、力输出)的规律。传感器方面,本文从电极形状、电解质膜结构、电解质离子尺寸3个方面,讨论了IPMC传感性能(如感应电压的幅值、稳定性)的优化技术。论文还展望了IPMC的未来发展方向。
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关键词:
- 电活性聚合物(EAP) /
- 离子交换聚合物/金属复合材料(IPMC) /
- 驱动器 /
- 传感器 /
- 力电耦合
Abstract: As flexible actuators and sensors, ion exchange polymer-metal composites (IPMCs) are widely used in bionic machinery, medical devices and other fields. Actuation is the main application of the IPMC, and IPMC actuators have bottlenecks such as low output power and unstable actuation. Sensing is another important application, and IPMC sensors endure some defects such as low induced voltage and large interference. For actuator, we discussed the modification techniques and driving characteristics of different polymer electrolytes, and focused on the structure-activity relationship of that, the compositions and structures the electrolytes determine their physical properties (e.g. ion exchange capacity, water uptake, mechanical property), subsequently determine their electromechanical properties (e.g. displacement, force outputs). For sensor, we discussed the optimization technologies of IPMC sensing properties (e.g. amplitude and stability of the induced voltage) from three aspects of electrode shape, electrolyte membrane structure and electrolyte ion size. We also discussed IPMC's future research. -
图 2 (a) 仿蝠鲼[20];(b) 仿乌龟[21];(c) 仿毛毛虫[22];(d) 仿蟑螂[23];(e) 仿蝴蝶[24];(f) 仿蜜蜂[26];(g) 五指机构[28];(h) 十指机构[29];(i) 流体开关[30];(j) 多自由度导管[31];(k) 仿生水仙花[24];(l) 仿连翘花[25];(m) 喉部传感器[32];(n) 智能手套[36] (中间为自制IPMC连续驱动截图)
Figure 2. (a) Bionic manta ray[20]; (b) Bionic turtle[21]; (c) Bionic caterpillar[22]; (d) Bionic cockroach[23]; (e) Bionic butterfly[24]; (f) Bionic bee[26]; (g) Five-finger mechanism[28]; (h) Ten-finger mechanism[29]; (i) Fluid switch[30]; (j) Multi-freedom catheter[31]; (k) Bionic daffodils[24]; (l) Bionic forsythia flower[25]; (m) Throat sensor[32]; (n) Smart gloves[36] (Middle: Continuous actuations of a self-made IPMC actuator)
图 3 三电极电解池(a);常规IPMC ((b), (c))和接枝聚(3, 4-乙烯二氧噻吩)(PEDOT)后IPMC ((d), (e))的截面示意图和SEM图像[40]
Figure 3. Three-electrode cell (a); Cross-sectional diagrams and SEM images of IPMC ((b), (c)) and poly(3,4-ethylenedioxythiophene) (PEDOT)-grafted IPMC ((d), (e))[40]
CE—Counter electrode; RE—Reference electrode; WE—Working electrode
图 4 (a) MXene的结构示意图;(b) 嵌入PEDOT的MXene;(c) MXene夹心的电解质膜[24];(d) 垂直排列碳纳米管(Va-CNT)的SEM图像;(e) CNT/全氟磺酸(Nafion)复合材料;(f) 复合电极切片的SEM图像[43];(g) IPMC的热压组装图[43]
PSS—Poly(styrenesulfonate)
Figure 4. (a) MXene flakes; (b) MXene electrode embedded with PEDOT; (c) MXene electrodes sandwiched electrolyte film[24]; (d) SEM image of vertically aligned carbon nanotubes (Va-CNT); (e) Schematic diagram of CNT/Nafion composite; (f) SEM image of CNT/Nafion slice; (g) Assembly drawing of IPMC by hot-press technique[43]
图 5 (a) AgNO3被还原为Ag(0),外表面包覆聚乙烯吡咯烷酮(PVP);(b) 利用浸涂(Dip-coating)将PVP@银纳米粒子(AgNPs)涂覆在废IPMC (IPMC-old)表面,得IPMC-repair;(c) 电场下,IPMC-repair稳定驱动[45]
Figure 5. (a) AgNO3 was reduced into Ag(0) seed which was coated by the polyvinyl pyrrolidone (PVP); (b) PVP@Ag nanoparticles (AgNPs) was coated on both surfaces of the futile IPMC (IPMC-old), thus obtained IPMC-repair; (c) Triggered by the electric field, IPMC-repair generated stable actuations[45]
v—Velocity
图 6 (a) 全氟磺酸(PFSA)的分子结构[56];(b) 内管道形成示意图[56];(c) 簇模型[57];(d) 3D内管道,提取出的3D离子相图像,显示了离子相的空间分布[58]
Figure 6. (a) Molecular structure of perfluorosulfonic acid (PFSA)[56]; (b) Schematic diagram of formation of the inner channels[56]; (c) Cluster model[57]; (d) 3D inner channels, the extracted 3D images displayed the spatial distribution of ion phase[58]
λ—Water content
图 8 (a) 含有离子液体(IL)的PVDF/PVP复合膜;((b)~(d)) 去除IL后,复合膜内部的多级内管道;(e) 水和IL驱动下IPMC的位移(蓝左),力输出(红右)[76]
Figure 8. (a) PVDF/PVP composite film containing ionic liquid (IL); ((b)-(d)) Multi inner channels inside the composite film after IL' removal; (e) Displacement (blue left) and force (red right) outputs of IPMC driven by water or IL[76]
Gr—Graphene; AC—Alternating current
图 13 (a) 离子交换当量(IEC);(b) 含水率(WU);(c) 杨氏模量(左为干膜,右为湿膜);(d) 偏转角;(e) 力输出 (A~H依次为Nafion、PVDF、磺化聚苯乙烯(SPS)、磺化聚芳砜(SPSU)、磺化微生物纤维素(SBC)、磺化壳聚糖(SCS)、磺化聚醚醚酮(SPEEK)、磺化聚乙烯醇(SPVA)复合物膜。图13(c)中实心数据来自拉伸模量,空心数据来自压缩模量。偏转角来自文献中数据,或驱动截图中的最大偏转部分。力输出为单位母体膜厚度的力输出)
Figure 13. (a) Ion exchange capacity (IEC); (b) Water uptake (WU); (c) Young's modulus (Left: Dry; Right: Wet); (d) Deflection angle; (e) Force output (A-H is Nafion, PVDF, sulfonated polystyrene (SPS), SPSU, sulfonated bacterial cellulose (SBC), sulfonated chitosan (SCS), sulfonated polyether ether ketone (SPEEK), sulfonated polyvinyl alcohol (SPVA) composite matrixes, respectively. In Fig.13(c), the solid data originated from the tensile moduli, while the dotted data were from the compression moduli. The deflection angle originated from the data in the literatures, or the maximum deflection sections in the actuation videos. The force outputs were the detected forces divided by the thickness, which were extracted from the data in the literatures
图 14 压力下的离子分布图(绿色为聚合物链网络,红色的为阳离子,蓝色的为阴离子[99]。工作(感应)电极被放置在凹痕部分下方,参比电极(接地)放置在凝胶的未形变区域)
Figure 14. Schematic of ion distribution under pressure[99] (Polymer chain network was colored in green, cations in red and anions in blue. The working (induction) electrode was placed below the dent and the reference electrode (ground) in the undeformed area)
图 17 压力传感器的工作原理:(a) 无压力;(b) 施加压力;(c) 解除压力[105]
Figure 17. Schematic exhibiting the working principle of pressure sensor: (a) No pressure; (b) Applied pressure; (c) Removed pressure[105]
MBOFH—Montmorillonite/borophene/organic solvent/regenerated silk fibroin (RSF)/hydrogel; TBIM—Topological borophene-bismuthene derivative micro-leaves; PEN—Polyethylene naphthalate; ITO—Indium-doped tin oxide
图 19 (a) 聚(偏二氟乙烯-co-六氟丙烯) (PVDF-HFP)/聚丙烯酰胺(PAM)复合水凝胶示意图;(b) 胶带封装的三明治结构传感器示意图;(c) 传感器对于超声波振动的电压输出响应[107]
Figure 19. (a) Schematic diagram of the polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)/poly(acrylamide) (PAM) composite hydrogel; (b) Schematic diagram of sandwich structure sensor wrapped in tape; (c) Voltage output response of sensor to ultrasonic vibration[107]
图 20 (a) 氯离子功能化离子电子压力敏感材料(CLiPS)传感器示意图;(b) 离子迁移传感机制:压力刺激前,离子对被Cl捕获(左);压力刺激后产生离子对的释放(右)[112]
Figure 20. (a) Cl-functionalized iontronic pressure sensitive material (CLiPS) based strain sensor; (b) Sensing mechanism based on ion migration: Ion pairs before pressure stimulation were trapped by Cl groups (left), release after stimulation (right)[112]
AgNW—Ag nanowires; PU—Polyurethane; EMIM+—(1-ethyl-3-methylimidazolium); TFSI−—Bis(trifluoromethylsulfonyl)imide
表 1 电活性聚合物(EAP)、压电(PZ)、形状记忆合金(SMA)的驱动参数比较
Table 1. Comparison of driving parameters of electroactive polymer (EAP), piezoelectric (PZ), and shape memory alloy (SMA)
Material Strain/% Stress/MPa Response speed Density/(g·cm−3) Driving voltage/V Mechanical property Ref. EAP DE 8-380 0.3-38 μs 1.5 > 1000 Elasticity [12-14] PZP 0.1-10 4.8-45 μs 1.78-8 > 1000 Elasticity [12, 13, 15] CP 2-40 5-200 ms-s 1.48 1-30 Soft [12, 15] IPMC 0.5-30 3-78 ms-s 1-2.5 1-7 Elasticity [12, 15-17] PZ 0.1-0.3 30-110 μs-s 6-8 50-800 Brittleness [13, 16] SMA 5-8 200-700 s-min 5-6 — Elasticity [12, 13, 15] Notes: DE—Dielectric elastomer; PZP—Piezoelectric polymer; CP—Conductive polymer; IPMC—Ion exchange polymer-metal composites. 表 2 电解质膜的参数比较
Table 2. Parameter comparisons for different electrolyte films
IEM IEC/(mmol·g−1) IC/(mS·cm−1) WU/wt% Y's (Dry、Wet)/MPa Ref. PFSA 0.62-1.66 10.5-130 6-41 160-450/39-320 [51, 61, 63, 73-74, 77, 81, 93-94] PFCA 1.44-1.8 110 24 170/— [66, 95-96] PVDF 0.48-4.21 0-114 10-199 712- 1400 /24-720[70-71, 73-74, 90, 92, 94] SPS 0.48-3.11 1.4-120 19-194 710- 1360 /31-210[69-70, 82, 93-94] SPSU 1.32-2.62 3.6-49.6 29-54 800- 1260 /220-630[50, 81] SBC 1.15-1.63 0-3.7 27-50 350-780/— [97] SCS 1.2-2.6 0-0.03 — 820- 1960 /—[84] SPEEK 1.58-2.30 6.2-62 28-40 870- 1830 /300-550[74, 86, 94] SPVA 0.25-1.8 1.5-28 36-181 266/3.4-140 [88, 91, 94] Notes: IEM—Ion exchange membrane; IC—Ionic conductivity; Y's—Young's modulus; PFCA—Perfluorocarbonic acid. -
[1] BAUGHMAN R H. Playing nature's game with artificial muscles[J]. Science, 2005, 308(5718): 63-65. doi: 10.1126/science.1099010 [2] LI G R, CHEN X P, ZHOU F H, et al. Self-powered soft robot in the Mariana Trench[J]. Nature, 2021, 591(7848): 66-71. doi: 10.1038/s41586-020-03153-z [3] CHU H T, HU X H, WANG Z, et al. Unipolar stroke, electroosmotic pump carbon nanotube yarn muscles[J]. Science, 2021, 371(6528): 494-498. doi: 10.1126/science.abc4538 [4] ZHANG Q M, BHARTI V, ZHAO X. Giant electrostriction and relaxor ferroelectric behavior in electron-irradiated poly(vinylidene fluoride-trifluoroethylene) copolymer[J]. Science, 1998, 280(5372): 2101-2104. doi: 10.1126/science.280.5372.2101 [5] PELRINE R, KORNBLUH R, PEI Q B, et al. High-speed electrically actuated elastomers with strain greater than 100%[J]. Science, 2000, 287(5454): 836-839. doi: 10.1126/science.287.5454.836 [6] HUANG J J, ZHANG X D, LIU R X, et al. Polyvinyl chloride-based dielectric elastomer with high permittivity and low viscoelasticity for actuation and sensing[J]. Nature Communications, 2023, 14(1): 1483. doi: 10.1038/s41467-023-37178-5 [7] 马丽, 丁井鲜, 张晓蝶, 等. MWCNT-CB/PDMS 复合电极介电弹性体驱动器的制备与性能优化[J]. 复合材料学报, 2023, 40(1): 291-299.MA li, DING Jingxian, ZHANG Xiaodie, et al. Fabrication and optimization of dielectric elastomer actuator using MWCNT-CB/PDMS composite electrodes[J]. Acta Materiae Compositae Sinica, 2023, 40(1): 291-299(in Chinese). [8] HUANG C, ZHANG Q M, JÁKLI A. Nematic anisotropic liquid-crystal gels: Self-assembled nanocomposites with high electromechanical response[J]. Advanced Functional Materials, 2003, 13(7): 525-529. doi: 10.1002/adfm.200304322 [9] MA M M, GUO L, ANDERSON D G, et al. Bio-inspired polymer composite actuator and generator driven by water gradients[J]. Science, 2013, 339(6116): 186-189. doi: 10.1126/science.1230262 [10] LU L H, LIU J H, HU Y, et al. Highly stable air working bimorph actuator based on a graphene nanosheet/carbon nanotube hybrid electrode[J]. Advanced Materials, 2012, 24(31): 4317-4321. doi: 10.1002/adma.201201320 [11] BAHRAMZADEH Y, SHAHINPOOR M. Dynamic curvature sensing employing ionic-polymer-metal composite sensors[J]. Smart Materials and Structures, 2011, 20(9): 094011. doi: 10.1088/0964-1726/20/9/094011 [12] ARIANO P, ACCARDO D, LOMBARDI M, et al. Polymeric materials as artificial muscles: An overview[J]. Journal of Applied Biomaterials & Functional Materials, 2015, 13(1): 1-9. [13] PELRINE R, KORNBLUH R, JOSEPH J, et al. High-field deformation of elastomeric dielectrics for actuators[J]. Materials Science and Engineering: C, 2000, 11(2): 89-100. doi: 10.1016/S0928-4931(00)00128-4 [14] 刘立武, 李金嵘, 吕雄飞, 等. 电活性介电弹性体的本构理论和稳定性研究进展[J]. 中国科学: 技术科学, 2015, 45(5): 450-463. doi: 10.1360/N092014-00433LIU Liwu, LI Jinrong, LYU Xiongfei, et al. Progress in constitutive theory and stability research of electroactive dielectric elastomers[J]. Scientia Sinica (Technologica), 2015, 45(5): 450-463(in Chinese). doi: 10.1360/N092014-00433 [15] MAKSIMKIN A V, DAYYOUB T, TELYSHEV D V, et al. Electroactive polymer-based composites for artificial muscle-like actuators: A review[J]. Nanomaterials, 2022, 12(13): 2272. doi: 10.3390/nano12132272 [16] O'HALLORAN A, O'MALLEY F, MCHUGH P. A review on dielectric elastomer actuators, technology, applications, and challenges[J]. Journal of Applied Physics, 2008, 104(7): 071101. doi: 10.1063/1.2981642 [17] WANG H, YANG L, YANG Y N, et al. Highly flexible, large-deformation ionic polymer metal composites for artificial muscles: Fabrication, properties, applications, and prospects[J]. Chemical Engineering Journal, 2023, 469: 143976. doi: 10.1016/j.cej.2023.143976 [18] ZHANG H, LIN Z H, HU Y, et al. Low-voltage driven ionic polymer-metal composite actuators: Structures, materials, and applications[J]. Advanced Science, 2023, 10(10): 2206135. doi: 10.1002/advs.202206135 [19] HE Q S, YIN G X, VOKOUN D, et al. Review on improvement, modeling, and application of ionic polymer metal composite artificial muscle[J]. Journal of Bionic Engineering, 2022, 19(2): 279-298. doi: 10.1007/s42235-022-00153-9 [20] CHEN Z, UM T I, BART-SMITH H. A novel fabrication of ionic polymer-metal composite membrane actuator capable of 3-dimensional kinematic motions[J]. Sensors and Actuators A: Physical, 2011, 168(1): 131-139. doi: 10.1016/j.sna.2011.02.034 [21] SUN Q M, HAN J Z, LI H, et al. A miniature robotic turtle with target tracking and wireless charging systems based on IPMCs[J]. IEEE Access, 2020, 8: 187156-187164. doi: 10.1109/ACCESS.2020.3026333 [22] CARRICO J D, HERMANS T, KIM K J, et al. 3D-printing and machine learning control of soft ionic polymer-metal composite actuators[J]. Scientific Reports, 2019, 9: 17482. doi: 10.1038/s41598-019-53570-y [23] WU Y C, YIM J K, LIANG J M, et al. Insect-scale fast moving and ultrarobust soft robot[J]. Science Robotics, 2019, 4(32): 1594. doi: 10.1126/scirobotics.aax1594 [24] UMRAO S, TABASSIAN R, KIM J, et al. MXene artificial muscles based on ionically cross-linked Ti3C2T x electrode for kinetic soft robotics[J]. Science Robotics, 2019, 4(33): 7797. doi: 10.1126/scirobotics.aaw7797 [25] MA S Q, ZHANG Y P, LIANG Y H, et al. High-performance ionic-polymer-metal composite: Toward large-deformation fast-response artificial muscles[J]. Advanced Functional Materials, 2019, 30(7): 1908508. [26] XU Z J, ZHU B, LIU X, et al. High-performance electroionic artificial muscles boosted by superior ion transport with Ti3C2T x MXene/cellulose nanocomposites for advanced 3D-motion actuation[J]. Chemical Engineering Journal, 2023, 477: 147246. doi: 10.1016/j.cej.2023.147246 [27] ZHAO Y, XU D, SHENG J Z, et al. Biomimetic beetle-inspired flapping air vehicle actuated by ionic polymer-metal composite actuator[J]. Applied Bionics and Biomechanics, 2018, 2018: 3091579. [28] WU G, WU X J, XU Y J, et al. High-performance hierarchical black-phosphorous-based soft electrochemical actuators in bioinspired applications[J]. Advanced Materials, 2019, 31(25): 1806492. doi: 10.1002/adma.201806492 [29] MAHATO M, TABASSIAN R, NGUYEN V H, et al. CTF-based soft touch actuator for playing electronic piano[J]. Nature Communications, 2020, 11(1): 5358. doi: 10.1038/s41467-020-19180-3 [30] MAHATO M, GARAI M, NGUYEN V H, et al. Polysulfonated covalent organic framework as active electrode host for mobile cation guests in electrochemical soft actuator[J]. Science Advances, 2023, 9(50): 9752. doi: 10.1126/sciadv.adk9752 [31] WANG Y J, LIU J Y, ZHU D L, et al. Active tube-shaped actuator with embedded square rod-shaped ionic polymer-metal composites for robotic-assisted manipulation[J]. Applied Bionics and Biomechanics, 2018, 2018: 4031705. [32] WANG M, MU L, ZHANG H, et al. Flexible strain sensor with ridge-like microstructures for wearable applications[J]. Polymers for Advanced Technologies, 2021, 33(1): 96-103. [33] LIU Y, HU Y, ZHAO J J, et al. Self-powered piezoionic strain sensor toward the monitoring of human activities[J]. Small, 2016, 12(36): 5074-5080. doi: 10.1002/smll.201600553 [34] LEE J H, CHEE P S, LIM E H, et al. Artificial intelligence-assisted throat sensor using ionic polymer-metal composite (IPMC) material[J]. Polymers, 2021, 13(18): 3041. doi: 10.3390/polym13183041 [35] LOW J H, CHEE P S, LIM E H, et al. Kirigami-inspired self-powered pressure sensor based on shape fixation treatment in IPMC material[J]. Smart Materials and Structures, 2024, 33(2): 025029. doi: 10.1088/1361-665X/ad1def [36] MING Y, YANG Y, FU R P, et al. IPMC sensor integrated smart glove for pulse diagnosis, braille recognition, and human-computer interaction[J]. Advanced Materials Technologies, 2018, 3(12): 1800257. doi: 10.1002/admt.201800257 [37] CHANG L F, WANG D P, HU J J, et al. Hierarchical structure fabrication of IPMC strain sensor with high sensitivity[J]. Frontiers in Materials, 2021, 8: 748687. doi: 10.3389/fmats.2021.748687 [38] ZHU Z C, BIAN C S, BAI W F, et al. Integrated fabrication process with multiple optimized factors for high power density of IPMC actuator[J]. International Journal of Smart and Nano Materials, 2022, 13(4): 643-667. doi: 10.1080/19475411.2022.2133187 [39] YU M, HE Q S, DING Y, et al. Force optimization of ionic polymer metal composite actuators by an orthogonal array method[J]. Chinese Science Bulletin, 2011, 56(19): 2061-2070. doi: 10.1007/s11434-011-4509-9 [40] GUO D J, WANG L, WANG X J, et al. PEDOT coating enhanced electromechanical performances and prolonged stable working time of IPMC actuator[J]. Sensors and Actuators B: Chemical, 2020, 305: 127488. doi: 10.1016/j.snb.2019.127488 [41] FUKUSHIMA T, ASAKA K, KOSAKA A, et al. Fully plastic actuator through layer-by-layer casting with ionic-liquid-based bucky gel[J]. Angewandte Chemie-International Edition, 2005, 44(16): 2410-2413. doi: 10.1002/anie.200462318 [42] WU C H, MENG W J, YOSHIO M. Low-voltage-driven actuators using photo-cross-linked ionic columnar liquid-crystalline polymer films[J]. ACS Materials Letters, 2021, 4(1): 153-158. [43] LIU S, LIU Y, CEBECI H, et al. High electromechanical response of ionic polymer actuators with controlled-morphology aligned carbon nanotube/nafion nanocomposite electrodes[J]. Advanced Functional Materials, 2010, 20(19): 3266-3271. doi: 10.1002/adfm.201000570 [44] SHAHINPOOR M, KIM K J. Experimental study of ionic polymer-metal composites in various cation forms: Actuation behavior[J]. Science and Engineering of Composite Materials, 2002, 10(6): 423-436. doi: 10.1515/SECM.2002.10.6.423 [45] WANG F, ZHANG X D, MA L, et al. Facile and effective repair of Pt/Nafion IPMC actuator by dip-coating of PVP@AgNPs[J]. Nanotechnology, 2021, 32(38): 385502. doi: 10.1088/1361-6528/ac0cae [46] KWON K S, NG T N. Improving electroactive polymer actuator by tuning ionic liquid concentration[J]. Organic Electronics, 2014, 15(1): 294-298. doi: 10.1016/j.orgel.2013.11.026 [47] ZHAO J J, HAN S, YANG Y, et al. Passive and space-discriminative ionic sensors based on durable nanocomposite electrodes toward sign language recognition[J]. ACS Nano, 2017, 11(9): 8590-8599. doi: 10.1021/acsnano.7b02767 [48] LEE J W, YOO Y T. Anion effects in imidazolium ionic: Liquids on the performance of IPMCs[J]. Sensors and Actuators B: Chemical, 2009, 137(2): 539-546. doi: 10.1016/j.snb.2009.01.041 [49] MUST I, VUNDER V, KAASIK F, et al. Ionic liquid-based actuators working in air: The effect of ambient humidity[J]. Sensors and Actuators B: Chemical, 2014, 202: 114-122. doi: 10.1016/j.snb.2014.05.074 [50] GUO D J, LIU R, LI Y K, et al. Polymer actuators of fluorene derivatives with enhanced inner channels and mechanical performance[J]. Sensors and Actuators B: Chemical, 2018, 255: 791-799. doi: 10.1016/j.snb.2017.08.119 [51] HAN Y B, WANG F, LI H K, et al. Sulfonic SiO2 nanocolloid doped perfluorosulfonic acid films with enhanced water uptake and inner channel for IPMC actuators[J]. RSC Advances, 2019, 9(72): 42450-42458. doi: 10.1039/C9RA07488K [52] HE Q S, YU M, SONG L L, et al. Experimental study and model analysis of the performance of IPMC membranes with various thickness[J]. Journal of Bionic Engineering, 2011, 8(1): 77-85. doi: 10.1016/S1672-6529(11)60001-2 [53] BIAN C S, ZHU Z C, BAI W F, et al. Highly efficient structure design of bending stacking actuators based on IPMC with large output force[J]. Smart Materials and Structures, 2021, 30(7): 075033. doi: 10.1088/1361-665X/ac0398 [54] WANG H S, CHO J, SONG D S, et al. High-performance electroactive polymer actuators based on ultrathick ionic polymer-metal composites with nanodispersed metal electrodes[J]. ACS Applied Materials & Interfaces, 2017, 9(26): 21998-22005. [55] RUAN L X, YAO X N, CHANG Y F, et al. Properties and applications of the β phase poly(vinylidene fluoride)[J]. Polymers, 2018, 10(3): 228. doi: 10.3390/polym10030228 [56] KUSOGLU A, WEBER A Z. New insights into perfluorinated sulfonic-acid ionomers[J]. Chemical Reviews, 2017, 117(3): 987-1104. doi: 10.1021/acs.chemrev.6b00159 [57] HSU W Y, GIERKE T D. Ion transport and clustering in Nafion perfluorinated membranes[J]. Journal of Membrane Science, 1983, 13(3): 307-326. doi: 10.1016/S0376-7388(00)81563-X [58] ALLEN F I, COMOLLI L R, KUSOGLU A, et al. Morphology of hydrated as-cast Nafion revealed through cryo electron tomography[J]. ACS Macro Letters, 2014, 4(1): 1-5. [59] NAJI L, SAFARI M, MOAVEN S. Fabrication of SGO/Nafion-based IPMC soft actuators with sea anemone-like Pt electrodes and enhanced actuation performance[J]. Carbon, 2016, 100: 243-257. doi: 10.1016/j.carbon.2016.01.020 [60] 焦战士, 何青松, 郭东杰, 等. 磺酸化石墨烯掺杂的离子交换聚合物电致动器[J]. 复合材料学报, 2012, 29(5): 24-31.JIAO Zhanshi, HE Qingsong, GUO Dongjie, et al. Electro-actuators of sulfonated graphene hybrid ion-exchange polymer[J]. Acta Materiae Compositae Sinica, 2012, 29(5): 24-31(in Chinese). [61] YONG J S, YOUNG K S, PARK J O, et al. Enhanced ionic polymer metal composite actuator with porous nafion membrane using zinc oxide particulate leaching method[J]. Smart Materials and Structures, 2015, 24(3): 030007. [62] GUO D J, FU S J, TAN W, et al. A highly porous Nafion membrane templated from polyoxometalates-based supramolecule composite for ion-exchange polymer-metal composite actuator[J]. Journal of Materials Chemistry, 2010, 20(45): 10159-10168. doi: 10.1039/c0jm01161d [63] ZHAO D X, RU J, WANG T, et al. Performance enhancement of ionic polymer-metal composite actuators with polyethylene oxide[J]. Polymers, 2021, 14(1): 80. doi: 10.3390/polym14010080 [64] GUO D J, DING H T, WEI H J, et al. Hybrids perfluorosulfonic acid ionomer and silicon oxide membrane for application in ion-exchange polymer-metal composite actuators[J]. Science in China Series E: Technological Sciences, 2009, 52(10): 3061-3070. doi: 10.1007/s11431-009-0280-4 [65] LEE J W, YOO Y T, LEE J Y. Ionic polymer-metal composite actuators based on triple-layered polyelectrolytes composed of individually functionalized layers[J]. ACS Applied Materials & Interfaces, 2014, 6(2): 1266-1271. [66] NEMAT-NASSER S, WU Y. Comparative experimental study of ionic polymer-metal composites with different backbone ionomers and in various cation forms[J]. Journal of Applied Physics, 2003, 93(9): 5255-5267. doi: 10.1063/1.1563300 [67] ZHU Z C, CHANG L F, ASAKA K, et al. Comparative experimental investigation on the actuation mechanisms of ionic polymer-metal composites with different backbones and water contents[J]. Journal of Applied Physics, 2014, 115(12): 124903. doi: 10.1063/1.4869537 [68] LU LH, LIU J H, HU Y, et al. Graphene-stabilized silver nanoparticle electrochemical electrode for actuator design[J]. Advanced Materials, 2012, 25(9): 1270-1274. [69] LEE J Y, WANG H S, YOON B R, et al. Radiation-grafted fluoropolymers soaked with imidazolium-based ionic liquids for high-performance ionic polymer-metal composite actuators[J]. Macromolecular Rapid Communications, 2010, 31(21): 1897-1902. doi: 10.1002/marc.201000261 [70] MEHRAEEN S, SADEGHI S, CEBECI F Ç, et al. Polyvinylidene fluoride grafted poly(styrene sulfonic acid) as ionic polymer-metal composite actuator[J]. Sensors and Actuators A: Physical, 2018, 279: 157-167. doi: 10.1016/j.sna.2018.05.038 [71] NASEF M M, SAIDI H, DAHLAN K Z M. Single-step radiation induced grafting for preparation of proton exchange membranes for fuel cell[J]. Journal of Membrane Science, 2009, 339(1-2): 115-119. doi: 10.1016/j.memsci.2009.04.037 [72] QIU X P, LI W Q, ZHANG S C, et al. Microstructure and character of the PVDF-g-PSSA membrane prepared by solution grafting[J]. Journal of the Electrochemical Society, 2003, 150(7): 917-921. doi: 10.1149/1.1579033 [73] PANWAR V, CHA K, PARK J O, et al. High actuation response of PVDF/PVP/PSSA based ionic polymer metal composites actuator[J]. Sensors and Actuators B: Chemical, 2012, 161(1): 460-470. doi: 10.1016/j.snb.2011.10.062 [74] JEON J H, KANG S P, LEE S, et al. Novel biomimetic actuator based on SPEEK and PVDF[J]. Sensors and Actuators B: Chemical, 2009, 143(1): 357-364. doi: 10.1016/j.snb.2009.09.020 [75] LU J, KIM S G, LEE S, et al. A biomimetic actuator based on an ionic networking membrane of poly(styrene-alt-maleimide)-incorporated poly(vinylidene fluoride)[J]. Advanced Functional Materials, 2008, 18(8): 1290-1298. doi: 10.1002/adfm.200701133 [76] GUO D J, HAN Y B, HUANG J J, et al. Hydrophilic poly (vinylidene fluoride) film with enhanced inner channels for both water- and ionic liquid-driven ion-exchange polymer metal composite actuators[J]. ACS Applied Materials & Interfaces, 2019, 11(2): 2386-2397. [77] LUQMAN M, LEE J W, MOON K K, et al. Sulfonated polystyrene-based ionic polymer-metal composite (IPMC) actuator[J]. Journal of Industrial and Engineering Chemistry, 2011, 17(1): 49-55. doi: 10.1016/j.jiec.2010.10.008 [78] WANG X L, OH I K, CHENG T H. Electro-active polymer actuators employing sulfonated poly(styrene-ran-ethylene) as ionic membranes[J]. Polymer International, 2010, 59(3): 305-312. doi: 10.1002/pi.2775 [79] WANG X L, OH I K, KIM J B. Enhanced electromechanical performance of carbon nano-fiber reinforced sulfonated poly(styrene-b-[ethylene/butylene]-b-styrene) actuator[J]. Composites Science and Technology, 2009, 69(13): 2098-2101. doi: 10.1016/j.compscitech.2008.08.023 [80] NGUYEN K T, KO S Y, PARK J O, et al. Terrestrial walking robot with 2DoF ionic polymer-metal composite (IPMC) legs[J]. IEEE/ASME Transactions on Mechatronics, 2015, 20(6): 2962-2972. doi: 10.1109/TMECH.2015.2419820 [81] TANG Y J, XUE Z G, ZHOU X P, et al. Novel sulfonated polysulfone ion exchange membranes for ionic polymer-metal composite actuators[J]. Sensors and Actuators B: Chemical, 2014, 202: 1164-1174. doi: 10.1016/j.snb.2014.06.071 [82] KIM S S, JEON J H, KEE C D, et al. Electro-active hybrid actuators based on freeze-dried bacterial cellulose and PEDOT:PSS[J]. Smart Materials and Structures, 2013, 22(8): 085026. doi: 10.1088/0964-1726/22/8/085026 [83] WANG F, KIM S S, KEE C D, et al. Novel electroactive PVA-TOCN actuator that is extremely sensitive to low electrical inputs[J]. Smart Materials and Structures, 2014, 23(7): 074006. doi: 10.1088/0964-1726/23/7/074006 [84] JEON J H, CHEEDARALA R K, KEE C D, et al. Dry-type artificial muscles based on pendent sulfonated chitosan and functionalized graphene oxide for greatly enhanced ionic interactions and mechanical stiffness[J]. Advanced Functional Materials, 2013, 23(48): 6007-6018. doi: 10.1002/adfm.201203550 [85] ROUAIX S, CAUSSERAND C, AIMAR P. Experimental study of the effects of hypochlorite on polysulfone membrane properties[J]. Journal of Membrane Science, 2006, 277(1-2): 137-147. doi: 10.1016/j.memsci.2005.10.040 [86] TANG Y J, XUE Z G, XIE X L, et al. Ionic polymer-metal composite actuator based on sulfonated poly(ether ether ketone) with different degrees of sulfonation[J]. Sensors and Actuators A: Physical, 2016, 238: 167-176. doi: 10.1016/j.sna.2015.12.015 [87] CAO J L, ZHANG Z, YE L, et al. Construction of poly(vinyl alcohol)-based ionogels with continuous ion transport channels enables high performance ionic soft actuators[J]. Journal of Materials Chemistry A, 2023, 11(37): 19981-19995. doi: 10.1039/D3TA03726F [88] LEE J W, KIM J H, GOO N S, et al. Ion-conductive poly (vinyl alcohol)-based IPMCs[J]. Journal of Bionic Engineering, 2010, 7(1): 19-28. doi: 10.1016/S1672-6529(09)60194-3 [89] BASS P, ZHANG L, TU M B, et al. Enhancement of biodegradable poly(ethylene oxide) ionic-polymer metallic composite actuators with nanocrystalline cellulose fillers[J]. Actuators, 2018, 7(4): 72. doi: 10.3390/act7040072 [90] PARK J H, HAN M J, SONG D S, et al. Ionic polymer-metal composite actuators obtained from radiation-grafted cation- and anion- exchange membranes[J]. ACS Applied Materials & Interfaces, 2014, 6(24): 22847-22854. [91] KHAN A, INAMUDDIN, JAIN R K, et al. Development of sulfonated poly(vinyl alcohol)/aluminium oxide/graphene based ionic polymer-metal composite (IPMC) actuator[J]. Sensors and Actuators A: Physical, 2018, 280: 114-124. doi: 10.1016/j.sna.2018.07.027 [92] LEHTINEN T, SUNDHOLM G, HOLMBERG S, et al. Electrochemical characterization of PVDF-based proton conducting membranes for fuel cells[J]. Electrochimica Acta, 1998, 43(12-13): 1881-1890. doi: 10.1016/S0013-4686(97)10005-6 [93] WANG X L, OH I K, XU L. Electro-active artificial muscle based on irradiation-crosslinked sulfonated poly(styrene-ran-ethylene)[J]. Sensors and Actuators B: Chemical, 2010, 145: 635-642. doi: 10.1016/j.snb.2010.01.001 [94] JO C, PUGALB D, OHA I K, et al. Recent advances in ionic polymer-metal composite actuators and their modeling and applications[J]. Progress in Polymer Science, 2013, 38(7): 1037-1066. doi: 10.1016/j.progpolymsci.2013.04.003 [95] ASAKA K, FUJIWARA N, OGURO K, et al. State of water and ionic conductivity of solid polymer electrolyte membranes in relation to polymer actuators[J]. Journal of Electroanalytical Chemistry, 2001, 505(1-2): 24-32. doi: 10.1016/S0022-0728(01)00445-4 [96] DUNCAN A J, LEO D J, LONG T E. Beyond Nafion: Charged macromolecules tailored for performance as ionic polymer transducers[J]. Macromolecules, 2008, 41(21): 7765-7775. doi: 10.1021/ma800956v [97] KIM S S, JEON J H, KIM H I, et al. High-fidelity bioelectronic muscular actuator based on graphene-mediated and TEMPO-oxidized bacterial cellulose[J]. Advanced Functional Materials, 2015, 25(23): 3560-3570. doi: 10.1002/adfm.201500673 [98] SHAHINPOOR M, BAR-COHEN Y, SIMPSON J O, et al. Ionic polymer-metal composites (IPMCs) as biomimetic sensors, actuators and artificial muscles: A review[J]. Smart Materials and Structures, 1998, 7: 15-30. doi: 10.1088/0964-1726/7/6/001 [99] DOBASHI Y, YAO D, PETEL Y, et al. Piezoionic mechanoreceptors: Force-induced current generation in hydrogels[J]. Science, 2022, 376(6592): 502-507. doi: 10.1126/science.aaw1974 [100] LU C, CHEN X, ZHANG X H, et al. Highly sensitive artificial skin perception enabled by a bio-inspired interface[J]. ACS Sensors, 2023, 8(4): 1624-1629. doi: 10.1021/acssensors.2c02743 [101] ZHU Z C, HORIUCHI T, KRUUSAMÄE K, et al. The effect of ambient humidity on the electrical response of ion-migration-based polymer sensor with various cations[J]. Smart Materials and Structures, 2016, 25(5): 055024. doi: 10.1088/0964-1726/25/5/055024 [102] LU C, LIAO X B, FANG D N, et al. Highly sensitive ultrastable electrochemical sensor enabled by proton-coupled electron transfer[J]. Nano Letters, 2021, 21(12): 5369-5376. doi: 10.1021/acs.nanolett.1c01692 [103] LU C, YU X P, CHEN Y X, et al. Giant piezoionic effect of ultrathin MXene nanosheets toward highly-sensitive sleep apnea diagnosis[J]. Chemical Engineering Journal, 2023, 463: 142523. doi: 10.1016/j.cej.2023.142523 [104] LI L, PAN J L, CHANG L F, et al. A MXene heterostructure-based piezoionic sensor for wearable sensing applications[J]. Chemical Engineering Journal, 2024, 482: 148988. doi: 10.1016/j.cej.2024.148988 [105] ZHOU Y H, WANG Q, ZHANG X Y, et al. Piezoionic transfer effect in topological borophene-bismuthene derivative micro-leaves for robust supercapacitive electronic skins[J]. Nano Energy, 2022, 104: 107970. doi: 10.1016/j.nanoen.2022.107970 [106] HAN S, ZHAN J J, WANG D X, et al. Bionic ion channel and single-ion conductor design for artificial skin sensors[J]. Journal of Materials Chemistry B, 2017, 5(34): 7126-7132. doi: 10.1039/C7TB01760J [107] LU X, CHEN Y, ZHANG Y H, et al. Piezoionic high performance hydrogel generator and active protein absorber via microscopic porosity and phase blending[J]. Advanced Materials, 2024, 36(2): 07875. [108] LI F, CAI X Q, LIU G K, et al. Piezoionic SnSe nanosheets-double network hydrogel for self-powered strain sensing and energy harvesting[J]. Advanced Functional Materials, 2023, 33(32): 00701. [109] LU C, CHEN Y X, YU X P, et al. Graphene-enhanced double-network ionogel electrolytes for energy storage and strain sensing[J]. Polymer Bulletin, 2023, 80: 12895-12905. [110] LIU D S, RYU H J, KHAN U, et al. Piezoionic-powered graphene strain sensor based on solid polymer electrolyte[J]. Nano Energy, 2021, 81: 105610. doi: 10.1016/j.nanoen.2020.105610 [111] HE Q S, ZHONG Q Y, SUN Z, et al. Highly stretchable, repeatable, and easy-to-prepare ionogel based on polyvinyl chloride for wearable strain sensors[J]. Nano Energy, 2023, 113: 108535. doi: 10.1016/j.nanoen.2023.108535 [112] BOAHEN E K, PAN B H, KWEON H, et al. Ultrafast, autonomous self-healable iontronic skin exhibiting piezo-ionic dynamics[J]. Nature Communications, 2022, 13(1): 7699. doi: 10.1038/s41467-022-35434-8 -