Modular soft robots demonstrate significant advantages such as reconfigurability, environmental adaptability, and motion flexibility by integrating the characteristics of modular design and flexible materials. In this paper, we systematically sort out the current research status of modular soft robots, and analyze their design features and application scenarios according to the three composition modes of assembled, reconfigurable, and self-reconfigurable. In terms of drive modes, the paper focuses on the principles, performance and limitations of fluid drive, shape memory alloy (SMA) drive, electromagnetic drive, and other technologies. At the motion modes aspect, the principles and realization methods of bionic for crawling, jumping, rolling, and other modes are elaborated in detail. In addition, the innovations and challenges of inter-module connection technologies are systematically summarized in terms of connection modes, revealing their key roles in robot functional diversity and reconfigurability. Finally, this paper looks forward to future research directions, including the development of high-performance smart materials, drive efficiency optimization, artificial intelligence fusion, and application expansion in medical and industrial fields.
ArmaniniCBoyerFMathewAT, et al. Soft robots modeling: a structured overview. IEEE Trans Robot2023; 39(3): 1728–1748.
2.
BaoGZhangYXuZ, et al. Review on pneumatic-driven structure for soft robot. High Tech-Communication2019; 29: 467–479.
3.
YaoMBelkeCHCuiH, et al. A reconfiguration strategy for modular robots using origami folding. Int J Rob Res2019; 38(1): 73–89.
4.
XuFYJiangFYJiangQS, et al. Soft actuator model for a soft robot with variable stiffness by coupling pneumatic structure and jamming mechanism. IEEE Access2020; 8: 26356–26371.
5.
KalnMAIAygulCTurkmenA, et al. Design, fabrication, and locomotion analysis of an untethered miniature soft quadruped, squad. IEEE Robot Autom Lett2020; 5(3): 3854–3860.
6.
BaoJChenWXuJ.Kinematics modeling of a twisted and coiled polymer-based elastomer soft robot. IEEE Access2019; 7: 136792–136800.
7.
YinSYaoDRSongY, et al. Wearable and implantable soft robots. Chem Rev2024; 124(20): 11585–11636.
8.
ChenZWangYChenH, et al. A magnetic multi-layer soft robot for on-demand targeted adhesion. Nat Commun2024; 15(1): 644.
9.
YangWWangXGeZ, et al. Magnetically controlled millipede inspired soft robot for releasing drugs on target area in stomach. IEEE Robot Autom Lett2024; 9: 3846–3853.
10.
XiaXMengJQinJ, et al. 4D-printed bionic soft robot with superior mechanical properties and fast near-infrared light response. ACS Appl Polym Mater2024; 6(6): 3170–3178.
11.
SunJYaoMXiaoX, et al. Co-optimization of morphology and behavior of modular robots via hierarchical deep reinforcement learning. Robot Sci Syst2023; 10–14.
12.
SunLWanJDuT.Fully 3D-printed tortoise-like soft mobile robot with muti-scenario adaptability. Bioinspir Biomim2023; 18(6): 066011.
13.
DasRBabuSPMVisentinF, et al. An earthworm-like modular soft robot for locomotion in multi-terrain environments. Sci Rep2023; 13(1): 1571.
14.
AtiaMGBMohammadAGamerosA, et al. Reconfigurable soft robots by building blocks. Adv Sci2022; 9(33): 1–15.
15.
SuiXCaiHBieD, et al. Automatic generation of locomotion patterns for soft modular reconfigurable robots. Appl Sci2019; 10: 294.
16.
PhillipsBTBeckerKPKurumayaS, et al. A dexterous, glove-based tele-operable low-power soft robotic arm for delicate deep-sea biological exploration. Sci Rep2018; 8: 1–9.
17.
IonescuDFilipescuASimionG, et al. Communication and control of an assembly, disassembly and repair flexible manufacturing technology on a mechatronics line assisted by an autonomous robotic system. Inventions2022; 7(2): 43.
18.
NeppalliSJonesBMcmahanW, et al. Oct-arm-a soft robotic manipulator. In: IEEE/RSJ International Conference, 2007, pp.2069–2569.
19.
KurumayaSPhillipsBTBeckerKP, et al. A modular soft robotic wrist for underwater manipulation. Soft Robot2018; 5(4): 399–409.
20.
FangBSunFWuL, et al. Multimode grasping soft gripper achieved by layer jamming structure and tendon-driven mechanism. Soft Robot2022; 9(2): 233–249.
21.
ItoHYamamotoKMoriH, et al. Efficient multitask learning with an embodied predictive model for door opening and entry with whole-body control. Sci Robot2022; 7(65): eaax8177.
22.
KabirSAslansefatKSorokosI, et al. A hybrid modular approach for dynamic fault tree analysis. IEEE Access2020; 8: 97175–97188.
23.
JiaoZZhangCWangW, et al. Advanced artificial muscle for flexible material-based reconfigurable soft robots. Adv Sci2019; 6(21): 1901371.
24.
KwokSWMorinSAMosadeghB, et al. Magnetic assembly of soft robots with hard components. Adv Funct2014; 24(15): 2180–2187.
25.
WuSZhaoTZhuY, et al. Modular multi-degree-of-freedom soft origami robots with reprogrammable electrothermal actuation. Proc Natl Acad Sci USA2024; 121(20): e2322625121.
26.
GómezJG. Modular robotics and locomotion: application to limbless robots. Pdd. Universidad Auto no made Madrid. Madrid, 2008, 42.
27.
DaiYHeSNieX, et al. Research on reconfiguration strategies for self-reconfiguring modular robots: a review. J Intell Robot Syst2024; 110(2): 47.
28.
TanNHayatAAElaraMR, et al. A framework for taxonomy and evaluation of self-reconfigurable robotic systems. IEEE Access2020; 8: 13969–13986.
29.
VuLATBiZMuellerD, et al. Modular self-configurable robots—the state of the art. Actuators2023; 12(9): 361.
30.
HauserSMutluMLéziartPA, et al. Room-bots extended: challenges in the next generation of self-reconfigurable modular robots and their application in adaptive and assistive furniture. Robot Auton Syst2020; 127: 103467.
31.
DokuyucuHİÖzmenNG. Achievements and future directions in self-reconfigurable modular robotic systems. J Field Robot2023; 40(3): 701–746.
32.
LinYYangGLiangY, et al. Controllable stiffness origami “skeletons” for lightweight and multifunctional artificial muscles. Adv Funct Mater2020; 30(31): 2000349.
33.
LouJLiuZYangL, et al. A new strategy of discretionarily reconfigurable actuators based on self-healing elastomers for diverse soft robots. Adv Funct Mater2021; 31(11): 2008328.
34.
KarimiMAAlizadehyazdiVJaegerHM, et al. A self-reconfigurable variable-stiffness soft robot based on boundary-constrained modular units. IEEE Trans Robot2022; 38(2): 810–821.
35.
RomanishinJWGilpinKRusD.M-blocks: momentum-driven, magnetic modular robots. In: 2013 IEEE/RSJ international conference on intelligent robots and systems, 2013, pp.4288–4295.
36.
GauciMOrtizMERubensteinM, et al. Error cascades in collective behavior: a case study of the gradient algorithm on 1000 physical agent. In: Proceedings of the 16th conference on autonomous agents and multi-agent systems, 2017, pp.1404–1412.
37.
SpröwitzAMoeckelRVespignaniM, et al. Roombots: a hardware perspective on 3D self-reconfiguration and locomotion with a homogeneous modular robot. Robot Auton Syst2014; 62(7): 1016–1033.
YangPHuangBMcCoulD, et al. Spring-worm: a soft crawling robot with a large-range omnidirectional deformable rectangular spring for control rod drive mechanism inspection. Soft Robot2023; 10(2): 280–291.
40.
JamilBOhNLeeJG, et al. A review and comparison of linear pneumatic artificial muscles. Int J Precis Eng Manuf Technol2024; 11(1): 277–289.
41.
SuHHouXZhangX, et al. Pneumatic soft robots: challenges and benefits. Actuators2022; 11(3): 92.
42.
SmithGLTylerJBLazarusN, et al. Spider-inspired, fully 3D-printed micro-hydraulics for tiny, soft robotics. Adv Funct Mater2023; 33(39): 2207435.
43.
LeeSHerIJungW, et al. Snakeskin-inspired 3d printable soft robot composed of multi-modular vacuum-powered actuators. Actuators2023; 12(2): 62.
44.
DawoodABFrasJAljaberF, et al. Fusing dexterity and perception for soft robot-assisted minimally invasive surgery: what we learnt from STIFF-FLOP. Appl Sci2021; 11(14): 6586.
45.
WehnerMTrubyRLFitzgeraldDJ, et al. An integrated design and fabrication strategy for entirely soft, autonomous robots. Nature2016; 536(7617): 451–455.
46.
JinLZhaiXZhangK, et al. 3D printing soft robots integrated with low-melting-point alloys. Materials Science in Additive Manufacturing2024; 3(3): 4144.
47.
KimMSHeoJKRodrigueH, et al. Shape memory alloy (SMA) actuators: the role of material, form, and scaling effects. Adv Mater2023; 35(33): 2208517.
48.
QiuJJiAZhuK, et al. A gecko-inspired robot with a flexible spine driven by shape memory alloy springs. Soft Robot2023; 10(4): 713–723.
49.
WeiSZhangJZhangL, et al. Laser powder bed fusion additive manufacturing of Ni-Ti shape memory alloys: a review. Int J Extrem Manuf2023; 5(3): 032001.
50.
HuQChenZDongE, et al. Design and control of a modular, untethered soft origami robot driven by SMA coils. IEEE Trans Ind Electron2025; 72: 8208–8218.
51.
HuQDongESunD.Soft modular climbing robots. IEEE Trans Robot2023; 39(1): 399–416.
52.
LeeJHChungYSRodrigueH.Long shape memory alloy tendon-based soft robotic actuators and implementation as a soft gripper. Sci Rep2019; 9(1): 11251.
McCallumRWLewisLSkomskiR, et al. Practical aspects of modern and future permanent magnets. Annu Rev Mater Res2014; 44(1): 451–477.
59.
NiuFXueQCaoQ, et al. Magneto-soft robots based on multi-materials optimizing and heat-assisted in-situ magnetic domains programming. Int J Extrem Manuf2025; 7(5): 055506.
60.
DongYWangLXiaN, et al. Untethered small-scale magnetic soft robot with programmable magnetization and integrated multifunctional modules. Sci Adv2022; 8(25): eabn8932.
61.
LiHZhangZYiX, et al. Control of self-winding microrobot using an electromagnetic drive system: integration of movable electromagnetic coil and permanent magnet. Micromachines2024; 15(4): 438.
62.
DoTNPhanHNguyenT, et al. Miniature soft electromagnetic actuators for robotic applications. Adv Funct Mater2018; 28(18): 1800244.
63.
KohlsNDiasBMensahY, et al. Compliant electromagnetic actuator architecture for soft robotics. In: 2020 IEEE international conference on robotics and automation (ICRA), 2020, pp.9042–9049.
64.
YaoMXiaoXBelkeCH, et al. Optimal distribution of active modules in reconfiguration planning of modular robots. J Mech Robot2019; 11(1): 011017.
NemitzMPMihaylovPBarracloughTW, et al. Using voice coils to actuate modular soft robots: worm-bot, an example. Soft Robot2016; 3(4): 198–204.
67.
SayedMERobertsJOMcKenzieRM, et al. Limpet II: a modular, untethered soft robot. Soft Robot2021; 8(3): 319–339.
68.
MaksimkinAVDayyoubTTelyshevDV, et al. Electroactive polymer-based composites for artificial muscle-like actuators: a review. Nanomaterials2022; 12(13): 2272.
69.
MuffLFMillsASRiddleS, et al. Modular design of a polymer-bilayer-based mechanically compliant worm-like robot. Adv Mater2023; 35(18): 2210409.
MirvakiliSMLeroyASimD, et al. Solar-driven soft robots. Adv Sci2021; 8(8): 2004235.
72.
HuH.Recent advances of polymeric phase change composites for flexible electronics and thermal energy storage system. Compos B Eng2020; 195: 108094.
73.
TinsleyBCaponiSMcAteerL, et al. Peristaltic motion enabled by pneumatic artificial muscles (PAMs) as structural “soft–stiff” actuators in a modular worm-inspired robot. Biomimetics2024; 9(8): 447.
74.
Van StratumB. Multi-modal continuum model-based design for soft robotics. The Florida State University, 2024.
75.
LuoMWanZSunY, et al. Motion planning and iterative learning control of a modular soft robotic snake. Front Rob AI2020; 7: 599242.
76.
QinYWanZSunY, et al. Design, fabrication and experimental analysis of a 3-d soft robotic snake. In: 2018 IEEE international conference on soft robotics (RoboSoft), 2018. p. 77–82. IEEE.
77.
XiaojuanMOWenjieGEDonglaiZ, et al. Review: research status of miniature jumping robot. J Mech Eng2019; 55(15): 109–123.
78.
RaibertMH.Legged robots that balance. MIT Press, 1986.
79.
Ramirez SerranoFHyunNPSteinhardtE, et al. A springtail-inspired multimodal walking-jumping microrobot. Sci Robot2025; 10(99): eadp7854.
80.
ChenRYuanZGuoJ, et al. Legless soft robots capable of rapid, continuous, and steered jumping. Nat Commun2021; 12(1): 7028.
81.
LiuTYLiDDYeJ, et al. An integrated soft jumping robotic module based on liquid metals. Adv Eng Mater2021; 23(12): 2100515.
82.
Fernandes MinoriAJadhavSChenH, et al. Power amplification for jumping soft robots actuated by artificial muscles. Front Rob AI2022; 9: 844282.
83.
WangQDingJNLuXL, et al. Changzhou University. An electromagnetic-driven soft robot that mimics kangaroo jumping.:CN202110955844.1. 2023-01-17.
84.
LiZGaiQLeiM, et al. Development of a multi-tentacled collaborative underwater robot with adjustable roll angle for each tentacle. Ocean Eng2024; 308: 118376.
85.
PrestonDJJiangHJSanchezV, et al. A soft ring oscillator. Sci Robot2019; 4(31): eaaw5496.
86.
YaoDRKimIYinS, et al. Multimodal soft robotic actuation and locomotion. Adv Mater2024; 36(19): 2308829.
87.
FanXChenQLiM, et al. Machining swarf formation-inspired fabrication of ferrofluidic helical miniature robots with multimodal locomotion capability. Sci Adv2025; 11(27): eads4411.
88.
HeZZhangQBiZ, et al. A multimodal metameric earthworm-like robot for locomotion in multi-terrain environments. In: IEEE/ASME transactions on mechatronics, 2024.
89.
HeJHuangPLiB, et al. Untethered soft robots based on 1D and 2D nanomaterials. Adv Mater2025; 37(9): 2413648.
90.
GuoYGuoJLiuL, et al. Bioinspired multimodal soft robot driven by a single dielectric elastomer actuator and two flexible electro-adhesive feet. Extrem Mech Lett2022; 53: 101720.
91.
HuangJZhouJWangZ, et al. Modular origami soft robot with the perception of interaction force and body configuration. Adv Intell Syst2022; 4: 2200081.
92.
ZhangYYangDYanP, et al. Inchworm inspired multimodal soft robots with crawling, climbing, and transitioning locomotion. IEEE Trans Robot2022; 38(3): 1806–1819.
93.
FangFLiWGuoX, et al. Hierarchically reconfigurable soft robots with reprogrammable multimodal actuation. Adv Funct Mater2025; 35(4): 2414279.
94.
WeiCZhangJLiuL, et al. Vinyl acetate-enhanced polyvinyl chloride gel with high electroadhesion and self-heating-tunability for soft robots in freezing environments. Adv Sci2025; 12: e07757.
95.
FangFZhouJZhangY, et al. A multimodal amphibious robot driven by soft electrohydraulic flippers. Cyborg Bionic Syst2025; 6: 0253.
96.
PanFLiuJZuoZ, et al. Miniature deep-sea morphable robot with multimodal locomotion. Sci Robot2025; 10(100): eadp7821.
97.
ZhangCZhuPLinY, et al. Modular soft robotics: modular units, connection mechanisms, and applications. Adv Intell Syst2020; 2(6): 1900166.
98.
FangZWuYSuY, et al. Omnidirectional compliance on cross-linked actuator coordination enables simultaneous multi-functions of soft modular robots. Sci Rep2023; 13(1): 12116.
99.
LuoYYaoMXiaoX. GCNT: graph-based transformer policies for morphology-agnostic reinforcement learning. In: Proceedings of the thirty-fourth international joint conference on artificial intelligence (IJCAI), 2025.
100.
ZhaoPYaoMXiaoX, et al. Concurrent optimization of modular robots for planetary landforms: a terrain-guided approach based on STGCN-GA. Astrodynamics2025; 9: 689–711.
101.
LeeMLeeJYoonJ, et al. Real-time physically-accurate simulation of robotic snap connection process. In: IEEE/RSJ international conference on intelligent robots and systems (IROS), 2021, pp.5173–5180.
102.
CondeJda SilvaLSTankovaT, et al. Design of pin connections between steel members. J Constr Steel Res2023; 201: 107752.
103.
ZhaoDZhangZZhaoJ, et al. A Mortise-and-Tenon joint inspired mechanically interlocked network. Angew Chem Int Ed2021; 60(29): 16224–16229.
104.
ZhaoLJiangYSheCY, et al. Soft-snap: rapid prototyping of untethered soft robots using snap-together modules. Soft Robot2025; 12: 698–707.
105.
YangHJinSWangWD.Modular assembly of soft machines via multidirectional re-closable fasteners. Adv Intell Syst2022; 4: 2200048.
106.
WuMZhengXLiuR, et al. Glowing sucker octopus (stauroteuthis syrtensis)-Inspired soft robotic gripper for underwater self-adaptive grasping and sensing. Adv Sci2022; 9(17): 2104382.
107.
UsevitchNSHammondZMSchwagerM, et al. An untethered isoperimetric soft robot. Sci Robot2020; 5(40): eaaz0492.
108.
SunQHouYChuZ, et al. Soft overcomes the hard: flexible materials adapt to cell adhesion to promote cell mechano-transduction. Bioact Mater2022; 10: 397–404.
109.
HeXWangWYangS, et al. Adhesive tapes: from daily necessities to flexible smart electronics. Appl Phys Rev2023; 10(1).
110.
SparrmanBdu PasquierCThomsenC, et al. Printed silicone pneumatic actuators for soft robotics. Addit Manuf2021; 40: 101860.
111.
ZhangSKeXJiangQ, et al. Fabrication and functionality integration technologies for small-scale soft robots. Adv Mater2022; 34(52): 2200671.
112.
QiXShiHPintoT, et al. A novel pneumatic soft snake robot using traveling-wave locomotion in constrained environments. IEEE Robot Autom Lett2020; 5(2): 1610–1617.
113.
López-DíazADe La MorenaJRamosF, et al. A novel hydrogel-based connection mechanism for soft modular robots. In: 2022 international conference on robotics and automation (ICRA), 2022, pp.7124–7130.
114.
ZhangYLiPQuanJ, et al. Progress, challenges, and prospects of soft robotics for space applications. Adv Intell Syst2023; 5(3): 2200071.
115.
ErlenbachSMondalKMaJ, et al. Flexible-to-stretchable mechanical and electrical interconnects. ACS Appl Mater Interfaces2023; 15(4): 6005–6012.
116.
HengWSolomonSGaoW.Flexible electronics and devices as human-machine interfaces for medical robotics. Adv Mater2022; 34(16): 2107902.
117.
LiuYHeKChenG, et al. Nature-inspired structural materials for flexible electronic devices. Chem Rev2017; 117(20): 12893–12941.
118.
XiongJChenJLeePS.Functional fibers and fabrics for soft robotics, wearables, and human-robot interface. Adv Mater2021; 33(19): 2002640.
119.
YangYWuYLiC, et al. Flexible actuators for soft robotics. Adv Intell Syst2020; 2(1): 1900077.
120.
GuoJXiangCRossiterJ.Electrically controllable connection and power transfer by electro-adhesion. Smart Mater Struct2019; 28(10): 105012.
121.
GermannJDommerMPericet-CamaraR, et al. Active connection mechanism for soft modular robots. Adv Robot2012; 26(7): 785–798.
122.
WangHZhuZJinH, et al. Magnetic soft robots: design, actuation, and function. J Alloys Comp2022; 922: 166219.
123.
KwonHYangYKimG, et al. Anisotropy in magnetic materials for sensors and actuators in soft robotic systems. Nanoscale2024; 16(14): 6778–6819.
124.
NongSSunYSunB, et al. Annelids-inspired modular design of multi-modal deformation for magnetic soft robots. Adv Funct Mater2025; 35: 2415690.
125.
KnosplerJXueWTrkovM.Reconfigurable modular soft robots with modulating stiffness and versatile task capabilities. Smart Mater Struct2024; 33(6): 065040.
126.
WangRWangJZhuZ, et al. Multimodal magnetic soft robots enabled by bistable kirigami patterns. IEEE/ASME Trans Mechatron2024; 29(6): 4526–4537.
127.
WangZMisraSVenkiteswaranVK.Multi-layer screen-printing of magnetic soft robots with integrated materials and functions. Cell Rep Phys Sci2025; 6: 102614.
128.
MichikawaRHosotaniKShimizuY, et al. Development and verification of connectors for modular robots to complete practical tasks on the moon. Artif Life Robot2025; 30(2): 198–207.
129.
SikdarSRahmanMHSiddaiahA, et al. Gecko-inspired adhesive mechanisms and adhesives for robots—a review. Robotics2022; 11(6): 143.
130.
HuQLiJDongE, et al. Soft scalable crawling robots enabled by programmable origami and electrostatic adhesion. IEEE Robot Autom Lett2023; 8(4): 2365–2372.
131.
HeQYinRHuaY, et al. A modular strategy for distributed, embodied control of electronics-free soft robots. Sci Adv2023; 9(27): eade9247.
132.
RajagopalanPMuthuMLiuY, et al. Advancement of electroadhesion technology for intelligent and self-reliant robotic applications. Adv Intell Syst2022; 4(7): 2200064.
133.
ChenWSuiJWangC.Magnetically actuated capsule robots: a review. IEEE Access2022; 10: 88398–88420.
134.
SokolichMRivasDYangY, et al. Modmag: a modular magnetic micro-robotic manipulation device. MethodsX2023; 10: 102171.
