Untethered, High-load Soft Gripping Robots: A Review

doi:10.3901/JME.2020.19.028

Abstract

Abstract: Due to the limitation of soft materials, fabrication, and key components, most soft robots have low load capacity and can not carry the hardware system for control and power. Therefore, they have to be tied to the external hardware through hoses and wires, which severely limits the operation scope and application fields of soft robots. Among many soft robots, the soft gripping robots have developed rapidly, mainly including two categories:One is the soft end effector, which mainly cooperate with manipulators, underwater robots, UAVs, and humans to complete the gripping operation; the other is movable soft grippers that have both a gripping function and a movement function, which realize the ingenious fusion of their own gripping structure and movement function. Aiming at the common topic of untethered optimization and high-load in the field of soft robotics, this paper focuses on the soft gripping robots with broad application prospects. The remarkable achievements and shortcomings in the development of soft gripping robots are analyzed from the aspects of untethered actuators, system integration, and load improvement. This paper also systematically summarizes the development technology and main challenges of untethered high-load soft gripping robots, providing a reference for the development direction and performance improvement of soft gripping robots, and promoting soft robots into the field of practical applications.

Key words: soft robots, soft gripping robots, untethered, hig

CLC Number:

TP242

LI Haili, YAO Jiantao, ZHOU Pan, ZHAO Wumian, XU Yundou, ZHAO Yongsheng. Untethered, High-load Soft Gripping Robots: A Review[J]. Journal of Mechanical Engineering, 2020, 56(19): 28-42.

Add to citation manager EndNote|Reference Manager|ProCite|BibTeX|RefWorks

URL: http://www.cjmenet.com.cn/EN/10.3901/JME.2020.19.028

http://www.cjmenet.com.cn/EN/Y2020/V56/I19/28

References

[1] RUS D,TOLLEY M T. Design,fabrication and control of soft robots[J]. Nature,2015,521(7553):467-475.
[2] LEE C,KIM M,KIM Y J,et al. Soft robot review[J]. International Journal of Control Automation & Systems. 2017,15(1):3-15.
[3] LASCHI C,MAZZOLAI B,CIANCHETTI M. Soft robotics:Technologies and systems pushing the boun-daries of robot abilities[J]. Science Robotics. 2016,1(1):UNSP eaah3690.
[4] 曹玉君,尚建忠,梁科山,等. 软体机器人研究现状综述[J]. 机械工程学报,2012,48(3):25-33. CAO Yujun,SHANG Jianzhong,LIANG Keshan,et al. Review of soft-bodied robots[J]. Journal of Mechanical Engineering,2012,48(3):25-33.
[5] 闫继宏,石培沛,张新彬,等. 软体机械臂仿生机理、驱动及建模控制研究发展综述[J]. 机械工程学报,2018,54(15):1-14. YAN Jihong,SHI Peipei,ZHANG Xinbin,et al. Review of biomimetic mechanism,actuation,modeling and control in soft manipulators[J]. Journal of Mechanical Engineering,2018,54(15):1-14.
[6] ZOU J,LIN Y Q,JI C,et al. A reconfigurable omni-directional soft robot based on caterpillar locomotion[J]. Soft Robotics,2018,5(2):164-174.
[7] PANG W,WANG J B,FEI Y Q. The structure,design,and closed-loop motion control of a differential drive soft robot[J]. Soft Robotics,2018,5(1):71-80.
[8] MARTINEZ R V,GLAVAN A C,KEPLINGER C,et al. Soft actuators and robots that are resistant to me-chanical damage[J]. Advanced Functional Materials,2014,24(20):3003-3010.
[9] KWOK S W,MORIN S A,MOSADEGH B,et al. Magnetic assembly of soft robots with hard components[J]. Advanced Functional Materials,2014,24(15):2180-2187.
[10] RICH S I,WOOD R J,MAJIDI C. Untethered soft robotics[J]. Nature Electronics,2018,1(2):102-112.
[11] PFEIFER R,LUNGARELLA M,IIDA F. The challenges ahead for bio-inspired soft robotics[J]. Communications of the ACM,2012,55(11):76-87.
[12] JUN S,VITO C,DARIO F,et al. Soft robotic grippers[J]. Advanced Materials,2018,30(29):1707035.
[13] 张进华,王韬,洪军,等. 软体机械手研究综述[J]. 机械工程学报,2017,53(13):19-28. ZHANG Jinhua,WANG Tao,HONG Jun,et al. Review of soft-bodied manipulator[J]. Journal of Mechanical Engineering,2017,53(13):19-28.
[14] HUGHES J,CULHA U,GIARDINA F,et al. Soft manipulators and grippers:A review[J]. Front Robot AI,2016,3:69.
[15] ZHAO H,O'BRIEN K,LI S,et al. Optoelectronically innervated soft prosthetic hand via stretchable optical waveguides[J]. Science Robotics,2016,1(1):eaai7529.
[16] SHE Y,LI C,CLEARY J,et al. Design and fabrication of a soft robotic hand with embedded actuators and sensors[J]. Journal of Mechanisms & Robotics,2015,7(2):021007.
[17] TERRYN S,BRANCART J,LEFEBER D,et al. Self-healing soft pneumatic robots[J]. Science Robotics,2017,2(9):eaan4268.
[18] LI Y,CHEN Y,YANG Y,et al. Passive particle jamming and its stiffening of soft robotic grippers[J]. IEEE Transactions on Robotics,2017,33(2):446-455.
[19] AL ABEACH L,NEFTIMEZIANI S,DAVIS S. Design of a variable stiffness soft dexterous gripper[J]. Soft Robotics,2017,4(3):274-284.
[20] NAGASE J,WAKIMOTO S,SATIH T,et al. Design of a variable stiffness robotic hand using pneumatic soft rubber actuators[J]. Smart Materials and Structure,2011,20(10):105015-105023.
[21] JANG D,JEONG J,SONG H,et al. Targeted drug delivery technology using untethered microrobots:A review[J]. Journal of Micromechanics and Microengin-eering,2019,29(5):053002.
[22] YIN C,WEI F,ZHAN Z,et al. Untethered micro-gripper-the dexterous hand at microscale[J]. Biomedical Microdevices,2019,21(4):82.
[23] YAP H K,NG H Y,YEOW CH. High-force soft printable pneumatics for soft robotic applications[J]. Soft Robotics,2016,3(3):144-158.
[24] LI H L,YAO J T,ZHOU P,et al. High-load soft grippers based on bionic winding effect[J]. Soft Robotics,2019,6(2):276-288.
[25] LI H L,YAO J T,ZHOU P,et al. Design and modeling of a high-load soft robotic gripper inspired by biological winding[J]. Bioinspiration&Biomimetics,2020,15(2):026006.
[26] LI H L,YAO J T,LIU C Y,et al. A bioinspired soft swallowing robot based on complaint guiding structure[J]. Soft Robotics,2020,DOI:10.1089/soro.2018. 0154.
[27] LI J X,DE ÁVILA B E F,GAO W,et al. Micro/nanorobots for biomedicine:Delivery,surgery,sensing,and detoxification[J]. Science Roboics,2017,2(4):eaam6431.
[28] HU W,LUM G Z,MASTRANGELI M,et al. Small-scale soft-bodied robot with multimodal locomotion[J]. Nature,2018,554(7690):81-85.
[29] MIYASHITA S,GUITRON S P,LUDERSDORFER M,et al. An untethered miniature origami robot that self-folds,walks,swims,and degrades[C]//IEEE International Conference on Robotics and Automation. IEEE,2015:15278285.
[30] ZHANG J C,DILLER E. Untethered miniature soft robots:Modeling and design of a millimeter-scale swim-ming magnetic sheet[J]. Soft robotics,2018,5(6):761-776.
[31] HOU M T,SHEN H M,JIANG G L,et al. A rolling locomotion method for untethered magnetic microro-bots[J]. Applied Physics Letters,2010,96(2):024102-024102-3.
[32] TEMEL F Z,ERMAN A G,YESILYURT S. Characterization and modeling of biomimetic untethered robots swimming in viscous fluids inside circular channels[J]. IEEE/ASME Transactions on Mechatronics,2014,19(5):1562-1573.
[33] PARK J E,JEON J,CHO J H,et al. Magnetomotility of untethered helical soft robots[J]. RSC Advances,2019,9(20):11272-11280.
[34] FLOYD S,PAWASHE C,SITTI M. Two-dimensional contact and noncontact micromanipulation in liquid using an untethered mobile magnetic microrobot[J]. IEEE Transactions on Robotics,2009,25(6):1332-1342.
[35] ICHIKAWA A,SAKUMA S,SUGITA M,et al. On-chip enucleation of an oocyte by untethered microrobots[J]. Journal of Micromechanics and Microengineering,2014,24(9):095004.
[36] FLOYD S,DILLER E,PAWASHE C,et al. Control methodologies for a heterogeneous group of untethered magnetic micro-robots[J]. The International Journal of Robotics Research,2011,30(13):1553-1565.
[37] IACOVACCI V,LUCARINI G,RICOTTI L,et al. Untethered magnetic millirobot for targeted drug deli-very[J]. Biomedical Microdevices,2015,17(3):9962.
[38] LI J Y,LI X J,LUO T,et al. Development of a magnetic microrobot for carrying and delivering targeted cells[J]. Science Robotics,2018,3(19):eaat8829.
[39] GILTINAN J,DILLER E,SITTI M. Programmable assembly of heterogeneous microparts by an untethered mobile capillary microgripper[J]. Lab on a Chip,2016,16(22):4445.
[40] TASOGLU S,DILLER E,GUVEN S,et al. Untethered micro-robotic coding of three-dimensional material com-position[J]. Nature Communications,2014,5:3124.
[41] BOYVAT M,KOH J S,WOOD R J,et al. Addressable wireless actuation for multijoint folding robots and devices[J]. Science Roboics,2017,2(8):eaan1544.
[42] KIM Y,PARADA G A,LIU S D,et al. Ferromagnetic soft continuum robots[J]. Science Roboics,2019,4(33):eaax7329.
[43] LEE W,NAM J,KIM J,et al. Effective locomotion and precise unclogging motion of an untethered flexible-legged magnetic robot for vascular diseases[J]. IEEE Transactions on Industrial Electronics,2018,65(2):1388-1397.
[44] YOONHO K,HYUNWOO Y,RUIKE Z,et al. Printing ferromagnetic domains for untethered fast-transforming soft materials[J]. Nature,2018,558(7709):274-279.
[45] ALASLI A,CETIN L,AKCURA N,et al. Electromagnet design for untethered actuation system mounted on robotic manipulator[J]. Sensors and Actuators A,2019,28:550-565.
[46] MAHONEY A W,ABBOTT J J. Five-degree-of-freedom manipulation of an untethered magnetic device in fluid using a single permanent magnet with application in stomach capsule endoscopy[J]. International Journal of Robotics Research,2016,35(1-3):129-147.
[47] MAHONEY A W,ABBOTT J J. Generating rotating magnetic fields with a single permanent magnet for propulsion of untethered magnetic devices in a lumen[J]. IEEE Transactions on Robotics,2014,30(2):411-420.
[48] GUPTA U,QIN L,WANG Y Z,et al. Soft robots based on dielectric elastomer actuators:A review[J]. Bioinspiration&Biomimetics,2019,28:103002.
[49] LI J,LIU L,LIU Y,et al. Dielectric elastomer spring-roll bending actuators:Applications in soft Robotics and design[J]. Soft Robotics,2019,6(1):69-81.
[50] SHOLL N,MOSS W M K,MOHSENI K. A soft end effector inspired by cephalopod suckers and augmented by a dielectric elastomer actuator[J]. Soft Robotics,2019,6(3):356-367.
[51] CHENG T Y,LI G,LIANG Y M,et al. Untethered soft robotic jellyfish[J]. Smart Materials and Structures,2019,28(1):015019.
[52] CAO J,QIN L,LEE H P,et al. Development of a soft untethered robot using artificial muscle actuators[C]//Electroactive Polymer Actuators and Devices (EAPAD). 2017,10163:UNSP 101631X.
[53] CAO J,QIN L,LIU J,et al. Untethered soft robot capable of stable locomotion using soft electrostatic actuators[J]. Extreme Mechanics Letters,2018,21:9-16.
[54] JI X B,LIU X C,CACUCCIOLO V,et al. An autonomous untethered fast soft robotic insect driven by low-voltage dielectric elastomer actuators[J]. Science Robotics,2019,4:eaaz6451.
[55] JAFFERIS N T,HELBLING E F,KARPELSON M,et al. Untethered flight of an insect-sized flapping-wing microscale aerial vehicle[J]. Nature,2019,570(7762):491-+.
[56] CACUCCIOLO V,SHIGEMUNE H,CIANCHETTI M,et al. Conduction electrohydrodynamics with mobile electrodes:A novel actuation system for untethered robots[J]. Advanced Science,2017,4(9):1600495.
[57] LI X,XIE J,TANG S Y,et al. A controllable untethered vehicle driven by electrically actuated liquid metal droplets[J]. IEEE Transactions on Industrial Informatics,2018,15(5):2535-2543.
[58] BAYTEKIN B,CEZAN S D,BAYTEKIN H T,et al. Artificial heliotropism and nyctinasty based on optome-chanical feedback and no electronics[J]. Soft Robot,2017,5(1):93-98.
[59] COARAL W,ROSSI C,CURET O M,et al. Design and assessment of a flexible fish robot actuated by shape memory alloys[J]. Bioinspiration&Biomimetics,2018,13:056009.
[60] HUANG X N,KUMAR K,JAWED M K,et al. Chasing biomimetic locomotion speeds:Creating untethered soft robots with shape memory alloy actuators[J]. Science Robotics,2018,3:eaau7557.
[61] ONGARO F,JIN Q R,DE CUMIS U S,et al. Force characterization and analysis of thin film actuators for untethered microdevices[J]. API Advances,2019,9(5):055011.
[62] CHEN T,BILAL O R,SHEA K,et al. Harnessing bistability for directional propulsion of soft,untethered robots[J]. Proceedings of the National Academy of Sciences,2018,115(22):5698-5702.
[63] YUAN J K,NERI W,ZAKRI C,et al. Shape memory nanocomposite fibers for untethered high-energy micro-engines[J]. Science,2019,365:155-158.
[64] WANG W. Mechanical assembly of thermo-responsive polymer-based untethered shape-morphing structures[J]. Macromol. Mater. Eng. 2019,305(1):201900568.
[65] KOTIKIAN A,MCMAHAN C,DAVIDSON E C,et al. Untethered soft robotic matter with passive control of shape morphing and propulsion[J]. Science Robotics,2019,4:eaax7044.
[66] AHN C Y,LIANG X D,CAI H Q. Bioinspired design of light-powered crawling,squeezing,and jumping unte-thered soft robot[J]. Advanced Materials Technologies,2019,4(7):1900185.
[67] ZENG H,WANI O M,WASYLCZYK P,et al. Light-driven,caterpillar-inspired miniature inching robot[J]. Macromolecular Rapid Communications,2018,39(1):1700224.
[68] ROGOZ M,ZENG H,XUAN C,et al. Light-driven soft robot mimics caterpillar locomotion in natural scale[J]. Advanced Optical Materials,2016,4(11):1689-1694.
[69] ZENG H,WANI O M,WASYLCZY P,et al. Self-regulating iris based on light-actuated liquid crystal elastomer[J]. Advanced Materials,2017,29(30):1701814.
[70] PALAGI S,MARK A G,REIGH S Y,et al. Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots[J]. Nature Materials,2016,15:647-653.
[71] FRANCIS W,DUNNE A,DELANEY C,et al. Spiropyran based hydrogels actuators-walking in the light[J]. Sensors and Actuators B Chemical,2017,250:608-616.
[72] SHIN B J,HA J H,LEE M,et al. Hygrobot:A self-locomotive ratcheted actuator powered by environ-mental humidity[J]. Science Robotics,2018,3:eaar2629.
[73] MARCHESE A D,KATZSCHMANN R K,RUS D. A recipe for soft fluidic elastomer robots[J]. Soft Robotics,2015,2(1):7-25.
[74] MARCHESE A D,ONAL C D,RUS D. Autonomous soft robotic fish capable of escape maneuvers using fluidic elastomer actuators[J]. Soft Robotics,2014,1(1):75-87.
[75] WEN L,REN Z,SANTO V D,et al. Understanding fish linear acceleration using an undulatory biorobotic model with soft fluidic elastomer actuated morphing median fins[J]. Soft Robotics,2018,5(4):375-388.
[76] AUBIN C A,CHOUDHURY S,JEERCH R,et al. Electrolytic vascular systems for energy-dense robots[J]. Nature,2019,571:51-57.
[77] TOLLEY M T,SHEPHERD R F,MOSADEGH B,et al. A resilient,untethered soft robot[J]. Soft Robotics,2014,1(3):213-223.
[78] MITCHELL S K,WANG X G,ACOME E,et al. An easy-to-implement toolkit to create versatile and high-performance HASEL actuators for untethered soft robots[J]. Advanced Science,2019,6(14):1900178.
[79] WEHNER M,TOLLEY M T,et al. Pneumatic energy sources for autonomous and wearable soft robotics[J]. Soft Robotics,2014,1(4):263-274.
[80] TOLLEY M T,SHEPHERD R F,KARPELSON M,et al. An untethered jumping soft robot[C]//IEEE/RSJ International Conference on Intelligent Robots & Systems. IEEE,2014,DOI:10.1109/IROS.2014.6942615
[81] LOEPFE M,SCHUMACHER C M,LUSTENBERGER U B,et al. An untethered,jumping roly-poly soft robot driven by combustion[J]. Soft Robotics,2015,2(1):33-41.
[82] BARTLETT N W,TOLLEY M T,OVERVELDE J T B,et al. A 3D-printed,functionally graded soft robot powered by combustion[J]. Science,2015,349(6244):161-165.
[83] WEHNER M,TRUBY R L,FITZGERALD DJ,et al. An integrated design and fabrication strategy for entirely soft,autonomous robots[J]. Nature,2016,536:451-455.
[84] CHEN L Y,CHEN W J,XUE Y T,et al. An untethered soft chemo-mechanical robot with composite structure and optimized control[J]. Extreme Mechanics Letters,2019,27:27-33.
[85] FEINBERG A W,FEIGEL A,SEVKOPLYAS S S,et al. Muscular thin films for building actuators and powering devices[J]. Science,2007,317:1366-1370.
[86] PATINO T,MESTRE R,SANCHEZ S. Miniaturized soft bio-hybrid robotics:A step forward into healthcare applications[J]. Lab on a Chip,2016,16(19):3626-3630.
[87] KANG H W,LEE S J,KO I K,et al. A 3D bioprinting system to produce human-scale tissue constructs with structural integrity[J]. Nature Biotechnology,2016,34:312-319.
[88] CVETKOVIC C,RAMAN R,CHAN V,et al. Three-dimensionally printed biological machines pow-ered by skeletal muscle[J]. Proceedings of the National Academy of Sciences,2014,111(28):10125-10130.
[89] RAMAN R,CVETKOVIC C,UZEL S G M,et al. Optogenetic skeletal muscle-powered adaptive biological machines[J]. Proceedings of the National Academy of Sciences,2016,113(13):3497-3502.
[90] NAWROTH J C,LEE H,FEINBERG A W,et al. A tissue-engineered jellyfish with biomimetic propulsion[J]. Nature Biotechnology,2012,30(8):792-797.
[91] PARK S J,GAZZOLA M,PARK K S,et al. Phototactic guidance of a tissue-engineered soft-robotic ray[J]. Science,2016,353(6295):158-162.
[92] LEONARDO C,GALLOWAY K C,SIDDHARTH S,et al. Exploiting textile mechanical anisotropy for fabric-based pneumatic actuators[J]. Soft Robotics,2018,5(5):662-674.
[93] POLYGERINOS P,WANG Z,OVERVELDE J T B,et al. Modeling of soft fiber-reinforced bending actuators[J]. IEEE Transactions on Robotics,2015,31(3):778-789.
[94] WANG Z,POLYGERINOS P,OVERVELDE J T B,et al. Interaction forces of soft fiber reinforced bending actuators[J]. IEEE/ASME Transactions on Mechatronics,2017,22(2):717-727.
[95] BISHOP-MOSER J,KRISHNAN G,KIM C,et al. Design of soft robotic actuators using fluid-filled fiber-reinforced elastomeric enclosures in parallel combinations[C]//2012 IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE,2012,DOI:10.1109/IROS. 2012.6385966.
[96] SEDAL A,BRUDER D,BISHOP-MOSER J,et al. A continuum model for fiber-reinforced soft robot actuators[J]. Journal of Mechanisms and Robotics,2018,10(2):024501.
[97] CONNOLLY F,WALSH C J,BERTOLDI K. Automatic design of fiber-reinforced soft actuators for trajectory matching[J]. Proceedings of the National Academy of Sciences,2017,114(1):51-56.
[98] RAINIER N,MANUEL D R,CHEN P C Y,et al. A reconfigurable pneumatic bending actuator with replaceable inflation modules[J]. Soft Robotics,2018,5(3):304-317.
[99] FANG J,YUAN J P,WANG M M,et al. Novel accordion-inspired foldable pneumatic actuators for knee assistive devices[J]. Soft Robotics,2020,7(1):95-108.
[100] FELT W. Folded-tube soft pneumatic actuators for bending[J]. Soft Robotics,2019,6(2):174-183.
[101] SUN Z S,GUO Z H,TANG W. Design of wearable hand rehabilitation glove with soft hoop-reinforced pneumatic actuator[J]. J. Cent. South Univ.,2019,26:106-119.
[102] FU H,HO J,LEE K,et al. Interfacing soft and hard:A spring reinforced actuator[J]. 2020,7(1):44-58.
[103] PAEZ L,AGRWAL G,PAIK J. Design and analysis of a soft pneumatic actuator with origami shell reinforcement[J]. Soft Robotics,2016,3(3):109-119.
[104] ROBERTSON M A,SADEGHI H,FLOREZ J M,et al. Soft pneumatic actuator fascicles for high force and reliability[J]. Soft Robotics,2017,4(1):23-32.
[105] YI J,CHEN X,SONG C,et al. Fiber-reinforced origamic robotic actuator[J]. Soft Robotics,2018,5(1):81-92.
[106] ZOLFAGHARIAN A,KOUZANI A Z,KHOO S Y,et al. Evolution of 3D printed soft actuators[J]. Sensors and Actuators A:Physical,2016,250:258-272.
[107] BYRNE O,COULTER F,GLYNN M,et al. Additive manufacture of composite soft pneumatic actuators[J]. Soft robotics,2018,5(6):726-736.
[108] DU P C,CHEN T,TIBBITS S,et al. Design and computational modeling of a 3D printed pneumatic toolkit for soft robotics[J]. Soft Robotics,2019,6(5):657-663.
[109] ROBERTSON M A,PAIK J. New soft robots really suck:Vacuum-powered systems empower diverse capabilities[J]. Science Robotics,2017,2:eaan6357.
[110] LI S,VOGT D M,RUS D,et al. Fluid-driven origami-inspired artificial muscles[J]. Proceedings of the National Academy of Sciences,2017,114(50):13132-13137.
[111] LEE J G,RODRIGUE H. Origami-based vacuum pneumatic artificial muscles with large contraction ratios[J]. Soft Robotics,2018,6(1):109-117.
[112] TAWK C,IN HET PANHUIS M,SPINKS G M,et al. Bioinspired 3D printable soft vacuum actuators for locomotion robots,grippers and artificial muscles[J]. Soft Robotics,2018,5(6):685-694.
[113] JIANG P,YANG Y D,CHEN M Z Q,et al. A variable stiffness gripper based on differential drive particle jamming[J]. Bioinspiration & biomimetics,2019,14:036009.
[114] JIANG A,RANZANI T,GERBONI G,et al. Robotic granular jamming:Does the membrane matter[J]. Soft Robotics,2014,1(3):192-201.
[115] BAMOTRA A,WALIA P,PRITUJA A V,et al. Layer-jamming suction grippers with variable stiffness[J]. Journal of Mechanisms and Robotics,2019,11:035003.
[116] 刘晨,李卓远,陈花玲. 一种新型柔性静电吸附变刚度结构[J]. 西安交通大学学报,2018,52(12):23-29. LIU Chen,LI Zhuoyuan,CHEN Hualing. A novel flexible electrostatic adsorption variable stiffness structure[J]. Journal of Xi'An Jiaotong University,2018,52(12):23-29.
[117] WANG T,ZHANG J,LI Y,et al. Electrostatic layer jamming variable stiffness for soft robotics[J]. IEEE/ASME Transactions on Mechatronics,2019,24(2):424-433.
[118] ABEACH L A T A,NEFTI-MEZIANI S,DAVIS S. Design of a variable stiffness soft dexterous gripper[J]. Soft Robotics,2017,4(3):274-284.
[119] HASSANIN A F,SAMIA N M,THEO T,et al. The design and mathematical model of a novel variable stiffness extensor-contractor pneumatic artificial muscle[J]. Soft Robotics,2018,5(5):576-591.
[120] YOSHIDA S,MORIMOTO Y,ZHENG LY,et al. Multipoint bending and shape retention of a pneumatic bending actuator by a variable stiffness endoskeleton[J]. Soft Robotics,2018,5(6):718-725.
[121] ZHANG Y F,ZHANG N B,HINGORANI H,et al. Fast-response,stiffness-tunable soft actuator by hybrid multimaterial 3D printing[J]. Adv. Funct. Mater.,2019,29(15):1806698.
[122] LI Y T,CHEN Y H,YANG Y,et al. Passive particle jamming and its stiffening of soft robotic grippers[J]. IEEE Transactions on Robotics,2017,33(2):446-455.
[123] LI Y,CHEN Y,YANG Y,et al. Soft robotic grippers based on particle transmission[J]. IEEE/ASME Transactions on Mechatronics,2017,24(3):969-978.
[124] WEI Y,CHEN Y H,REN T,et al. A novel,variable stiffness robotic gripper based on integrated soft actuating and particle jamming[J]. Soft Robotics,2016,3(3):134-143.
[125] ZHAO Y Z,SHAN Y,GUO K D,et al. A soft continuum robot,with a large variable stiffness range,based on jamming[J]. Bioinspiration & Biomimetics,2019,14(6):066007.
[126] WANG W,YU C Y,SERRANO P A A,et al. Shape memory alloy-based soft finger with changeable bending length using targeted variable stiffness[J]. Soft Robotics,2019,DOI:10.1089/soro. 2018.0166.
[127] BROWN E,RODENBERG N,AMEND J,et al. Universal robotic gripper based on the jamming of granular material[J]. Proceedings of the National Academy of Sciences of the United States of America,2010,107(44):18809-18814.
[128] AMEND J R,BROWN E M,RODENBERG N,et al. A positive pressure universal gripper based on the jamming of granular material[J]. IEEE Transactions on Robotics,2012,28(2):341-350.
[129] AMEND J,CHENG N,FAKHOURI S,et al. Soft robotics commercialization:Jamming grippers from research to product[J]. Soft Robotics,2016,3(4):213-222.
[130] DANG Y,STOMMEL M,CHENG L K,et al. A soft ring-shaped actuator for radial contracting deformation:Design and modeling[J]. Soft Robotics,2019,6(4):444-454.
[131] ZHU T,YANG H,ZHANG W. A spherical self-adaptive gripper with shrinking of an elastic membrane[C]//International Conference on Advanced Robotics & Mechatronics. IEEE,2016:512-517.
[132] KRAHN J,FABBRO F,MENON C. A soft-touch gripper for grasping delicate objects[J]. IEEE/ASME Trans-actions on Mechatronics,2017,22(3):1276-1286.
[133] QIAO S L,LIU R Q,GUO H W,et al. Configuration design of an under-actuated robotic hand based on maximum grasping space[J]. Chinese Journal of Mechanical Engin-eering,2018,31(2):45-53.
[134] MISHRA A K,DOTTORE E D,SADEGHI A,et al. SIMBA:Tendon-driven modular continuum arm with soft reconfigurable gripper[J]. Frontiers in Robotics and AI,2017,4:doi:10.3389/frobt.2017.00004.
[135] WHITE E L,CASE J C,KRAMER-BOTTIGLIO R. A soft parallel kinematic mechanism[J]. Soft Robotics,2018,5(1):36-53.
[136] MANTI M,HASSAN T,PASSETTI G,et al. A bioinspired soft robotic gripper for adaptable and effective grasping[J]. Soft Robotics,2015,2(3):107-116.
[137] CASE J C,WHITE E L,SUNSPIRAL V,et al. Reducing actuator requirements in continuum robots through optimized cable routing[J]. Soft Robotics,2018,5(1):109-118.
[138] LIU C H,CHEN T L,CHIU C H,et al. Optimal design of a soft robotic gripper for grasping unknown objects[J]. Soft Robotics,2018,5(4):452-465.
[139] LIU C H,HUANG G F,CHIU C H,et al. Topology synthesis and optimal design of an adaptive compliant gripper to maximize output displacement[J]. Journal of Intelligent and Robotic Systems,2017,90(5):1-18.
[140] DILLER E,SITTI M. Three-dimensional programmable assembly by untethered magnetic robotic micro-grippers[J]. Advanced Functional Materials,2014,24(28):4397-4404.
[141] MATHIEU J B,MATEL S. Steering of aggregating magnetic microparticles using propulsion gradients coils in an MRI scanner[J]. Magnetic Resonance in Medicine, 2010,63(5):1336-1345.
[142] MARTEL S,FELFOUL O,MATHIEU J B,et al. MRI-based medical nanorobotic platform for the control of magnetic nanoparticles and flagellated bacteria for target interventions in human capillaries[J]. Int. J. of Robotic Research,2009,28(9):1169-1182.
[143] SCHEGGI S,CHANDRASEKAR K K T,YOON C K,et al. Magnetic motion control and planning of untethered soft grippers using ultrasound image feedback[C]//2017 IEEE International Conference on Robotics and Automation (ICRA). IEEE,2017:6156-6161.
[144] ONGARO F,YOON C K,VAN DEN BRINK F,et al. Control of untethered soft grippers for pick-and-place tasks[C]//6th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob),IEEE,2016:299-304.
[145] GULTEPE E,RANDHAWA J S,KADAM S,et al. Biopsy with thermally-responsive untethered microtools[J]. Advanced Materials,2013,25(4):514-519.
[146] ONGARO F,SCHEGGI S,YOON C K,et al. Autonomous planning and control of soft untethered grippers in unstructured environments[J]. Journal of Micro-Bio Robotics,2017,12(1-4):45-52.
[147] PACCHIEROTTI C,ONGARO F,VAN DEN BRINK F,et al. Steering and control of miniaturized untethered soft magnetic grippers with haptic assistance[J]. IEEE Transactions on Automation Science and Engineering,2018,15(1):290-306.
[148] KOBAYASHI K,YOON C K,OH S H,et al. Biodegradable thermomagnetically responsive soft untethered grippers[J]. ACS Applied Materials & Interfaces,2019,11(1):151-159.
[149] SCHEGGI S,YOON C K,GHOSH A,et al. A GPU-accelerated model-based tracker for untethered submillimeter grippers[J]. Robotics and Autonomous Systems,2018,103:111-121.
[150] YIM S,GULTEPE E,GRACIAS D H,et al. Biopsy using a magnetic capsule endoscope carrying,releasing,and retrieving untethered microgrippers[J]. IEEE Transac-tions on Bio-medical Engineering,2014,61(2):513-521.
[151] QIAN X J,CHEN Q M,YANG Y,et al. Untethered recyclable tubular actuators with versatile locomotion for soft continuum robots[J]. Adv. Mater.,2018,30(29):1801103.
[152] AMJADI M,SITTI M. High-performance multiresponsive paper actuators[J]. ACS Nano,2016,10(11):10202-10210.
[153] WANI O M,ZENG H,PRIIMAGI A. A light-driven artificial flytrap[J]. Nature Communications,2017,8:15546.
[154] DA C M P,FOELEN Y,VAN RAAK R J H,et al. An untethered magnetic- and light-responsive rotary gripper:Shedding light on photoresponsive liquid crystal actuators[J]. Adv. Optical Mater.,2019,7(7):1801643
[155] DA CUNHA M P,FOELEN Y,ENGELS T A P,et al. On untethered,dual magneto-and photoresponsive liquid crystal bilayer actuators showing bending and rotating motion[J]. Advanced Optical Materials,2019,7(7):1801604.
[156] LI Y Q,CHEN Y H,REN T,et al. Precharged pneumatic soft actuators and their applications to untethered soft robots[J]. Soft Robotics,2018,5(5):567-575.
[157] SINATRA N R,TEEPLE C B,VOGT D M,et al. Ultragentle manipulation of delicate structures using a soft robotic gripper[J]. Science Robotics,2019,4:eaax5425.
[158] CHENGN,AMEND J,FARRELL T,et al. Prosthetic jamming terminal device:A case study of untethered soft robotics[J]. Soft Robotics,2016,3(4):205-212.
[159] GALLOWAY K C,BECHER K P,PHILLIPS B,et al. Soft robotic grippers for biological sampling on deep reefs[J]. Soft Robotics,2016,3(1):23-33.
[160] HAWKES E W,JIANG H,CHISTENSEN D L,et al. Grasping without squeezing:Design and modeling of shear-activated grippers[J]. IEEE Transactions on Robotics,2017,34(2):303-316.
[161] JUNG G P,KOH J S,CHO K J. Underactuated adaptive gripper using flexural buckling[J]. IEEE Transactions on Robotics,2013,29(6):1396-1407.
[162] CACUCCIOLO V,SHINTAKE J,KUWAJIMA Y,et al. Stretchable pumps for soft machines[J]. Nature,2019,572:516-519.
[163] ROTHEMUND P,AINLA A,BELDING L,et al. A soft,bistable valve for autonomous control of soft actuators[J]. Science Robotics,2018,3:eaar7986.
[164] TONAZZINI A,SADEGHI A,MAZZOLAI B. Electrorheological valves for flexible fluidic actuators[J]. Soft Robotics,2016,3(1):34-41.
[165] PARK S,VOSGUERICHIAN M,BAO Z. A review of fabrication and applications of carbon nanotube film-based flexible electronics[J]. Nanoscale,2013,5(5):1727.