PVC gel bio-inspired adhesives with variable modulus and its application in a gripper

Abstract

Inspired by the microstructure of gecko’s toe, two kinds of polyvinyl chloride (PVC) gels with different modulus were poured on a silicon mold with micropillars, and then a bio-inspired adhesive with variable modulus was manufactured in this study. The adhesions of variable modulus and fixed modulus bio-inspired adhesives were tested, respectively, on a smooth glass and a printed circuit board (PCB) with different surface structures. The results show that PVC gel bio-inspired adhesives with variable modulus have many advantages compared with the fixed modulus bio-inspired adhesives. The adhesion of variable modulus bio-inspired adhesives on the rough PCB surface increased by 2–5 times, and due to the use of variable modulus of PVC gel, the surface micropillars can maintain high aspect ratio and flexible tips at the same time. Moreover, the use of PVC gel makes it easier to demold during the bio-inspired adhesives preparation. An adhesion-desorption device was made according to the movement of the gecko toes, and the PCB was successfully grasped.

Keywords

bio-inspired adhesives / gecko / PVC gel / variable modulus

References

[1] AutumnK, DittmoreA, SantosD, et al.. Frictional adhesion: A new angle on gecko attachment [J]. The Journal of Experimental Biology, 2006, 209: 3569-3579 Pt 18

[2] ParkJ, ParkJ H, KimE, et al.. Conformable solid-index phase masks composed of high-aspect-ratio micropillar arrays and their application to 3D nanopatterning [J]. Advanced Materials (Deerfield Beach, Fla), 2011, 23(7): 860-864

[3] ZhangY-C, QuS-X, ChengX, et al.. Fabrication and characterization of gecko-inspired dry adhesion, superhydrophobicity and wet self-cleaning surfaces [J]. Journal of Bionic Engineering, 2016, 13(1): 132-142

[4] LiM, ZhaoA-W, JiangR, et al.. Regulation of the elastic modulus of polyurethane microarrays and its influence on gecko-inspired dry adhesion [J]. Applied Surface Science, 2011, 257(8): 3336-3340

[5] GongL, YuH-W, WuX, et al.. Wet-adhesion properties of microstructured surfaces inspired by newt footpads [J]. Smart Materials and Structures, 2018, 27(11): 114001

[6] KizilkanE, StruebenJ, StaubitzA, et al.. Bioinspired photocontrollable microstructured transport device [J]. Science Robotics, 2017, 22eaak9454

[7] KimT, ParkJ, SohnJ, et al.. Bioinspired, highly stretchable, and conductive dry adhesives based on 1D-2D hybrid carbon nanocomposites for all-in-one ECG electrodes [J]. ACS Nano, 2016, 1044770-4778

[8] HuH, TianH-M, ShaoJ-Y, et al.. Friction contribution to bioinspired mushroom-shaped dry adhesives [J]. Advanced Materials Interfaces, 2017, 4(9): 1700016

[9] YuanL-F, WangZ-W, LiY-Q, et al.. Reusable dry adhesives based on ethylene vinyl acetate copolymer with strong adhesion [J]. Journal of Applied Polymer Science, 2019, 1361347296

[10] KangS M. Bioinspired design and fabrication of green-environmental dry adhesive with robust wide-tip shape [J]. International Journal of Precision Engineering and Manufacturing-Green Technology, 2016, 32189-192

[11] JeongH E, SuhK Y. Nanohairs and nanotubes: Efficient structural elements for gecko-inspired artificial dry adhesives [J]. Nano Today, 2009, 4(4): 335-346

[12] HeQ-S, YuM, LiY, et al.. Adhesion characteristics of a novel synthetic polydimethylsiloxane for bionic adhesive pads [J]. Journal of Bionic Engineering, 2014, 11(3): 371-377

[13] ZhouM, TianY, SameotoD, et al.. Controllable interfacial adhesion applied to transfer light and fragile objects by using gecko inspired mushroom-shaped pillar surface [J]. ACS Applied Materials & Interfaces, 2013, 5(20): 10137-10144

[14] SongS, DrotlefD M, MajidiC, et al.. Controllable load sharing for soft adhesive interfaces on three-dimensional surfaces [J]. Proceedings of the National Academy of Sciences of the United States of America, 2017, 114(22): E4344-E4353

[15] MurphyM P, KimS, SittiM. Enhanced adhesion by gecko-inspired hierarchical fibrillar adhesives [J]. ACS Applied Materials & Interfaces, 2009, 1(4): 849-855

[16] KustandiT S, SamperV D, NgW S, et al.. Fabrication of a gecko-like hierarchical fibril array using a bonded porous alumina template [J]. Journal of Micromechanics and Microengineering, 2007, 17(10): N75-N81

[17] HeQ-S, XuX-R, YuZ-W, et al.. Optimized bio-inspired micro-pillar dry adhesive and its application for an unmanned aerial vehicle adhering on and detaching from a ceiling [J]. Journal of Bionic Engineering, 2020, 17(1): 45-54

[18] WangL-F, LiuJ-Q, DongY-Z, et al.. Polydimethyl-siloxane film for biomimetic dry adhesive integrated with capacitive biopotentials sensing [J]. Sensors and Actuators B: Chemical, 2014, 205: 168-175

[19] KimT I, JeongH E, SuhK Y, et al.. Polymeric nanohairs: Stooped nanohairs: Geometry-controllable, unidirectional, reversible, and robust gecko-like dry adhesive [J]. Advanced Materials, 2009, 21(22): 2276

[20] JeongH E, LeeJ K, KimH N, et al.. A nontransferring dry adhesive with hierarchical polymer nanohairs [J]. PNAS, 2009, 106145639-5644

[21] AutumnK, LiangY A, HsiehS T, et al.. Adhesive force of a single gecko foot-hair [J]. Nature, 2000, 405(6787): 681-685

[22] TanD, WangX, LiuQ, et al.. Switchable adhesion of micropillar adhesive on rough surfaces [J]. Small, 2019, 15(50): 1904248

[23] ShinE J, ParkW H, KimS Y. Fabrication of a highperformance bending actuator made with a PVC gel [J]. Applied Sciences, 2018, 881284

[24] HansenW R, AutumnK. Evidence for self-cleaning in gecko setae [J]. Proceedings of the National Academy of Sciences of the United States of America, 2005, 1022385-389

[25] WangY, HuH, ShaoJ-Y, et al.. Fabrication of well-defined mushroom-shaped structures for biomimetic dry adhesive by conventional photolithography and molding [J]. ACS Applied Materials & Interfaces, 2014, 6(4): 2213-2218

[26] SittiM, FearingR S. Synthetic gecko foot-hair micro/nano-structures as dry adhesives [J]. Journal of Adhesion Science and Technology, 2003, 17(8): 1055-1073

[27] GaoH-J, YaoH-M. Shape insensitive optimal adhesion of nanoscale fibrillar structures [J]. PNAS, 2004, 101(21): 7851-7856

[28] CañasN, KampermanM, VölkerB, et al.. Effect of nano- and micro-roughness on adhesion of bioinspired micropatterned surfaces [J]. Acta Biomaterialia, 2012, 8(1): 282-288

[29] YuM, HeQ-S, YuD-S, et al.. Efficient active actuation to imitate locomotion of gecko’s toes using an ionic polymer-metal composite actuator enhanced by carbon nanotubes [J]. Applied Physics Letters, 2012, 101(16): 163701

[30] TanD, ZhengY-J, XueL-J. The role of effective elastic modulus in the performance of structured adhesives. Biologically-Inspired Systems, 2017, Switzerland, Springer, 107-139

[31] HuH, TianH-M, ShaoJ-Y, et al.. Discretely supported dry adhesive film inspired by biological bending behavior for enhanced performance on a rough surface [J]. ACS Applied Materials & Interfaces, 2017, 9(8): 7752-7760

[32] BrodoceanuD, BauerC T, KronerE, et al.. Hierarchical bioinspired adhesive surfaces—A review [J]. Bioinspiration & Biomimetics, 2016, 11(5): 051001

[33] LeeS H, KimS W, KangB S, et al.. Scalable and continuous fabrication of bio-inspired dry adhesives with a thermosetting polymer [J]. Soft Matter, 2018, 14142586-2593