In this paper, a novel robotic gripper design with variable stiffness is proposed and fabricated using a modified additive manufacturing (hereafter called 3D printing) process. The gripper is composed of two identical robotic fingers and each finger has three rotational degrees-of-freedom as inspired by human fingers. The finger design is composed of two materials: acrylonitrile butadiene styrene (ABS) for the bone segments and shape-memory polymer (SMP) for the finger joints. When the SMP joints are exposed to thermal energy and heated to above their glass transition temperature (Tg), the finger joints exhibit very small stiffness, thus allow easy bending by an external force. When there is no bending force, the finger will restore to its original shape thanks to SMP's shape recovering stress. The finger design is actuated by a pneumatics soft actuator. Fabrication of the proposed robotic finger is made possible by a modified 3D printing process. An analytical model is developed to represent the relationship between the soft actuator's air pressure and the finger's deflection angle. Furthermore, analytical modeling of the finger stiffness modulation is presented. Several experiments are conducted to validate the analytical models.
Issue Section:
Research Papers
Keywords:
Bio-inspired design,
Compliant mechanisms,
Manufacturing,
Novel Fabrication Techniques,
Robot design,
Soft robots
Topics:
Actuators,
Deflection,
Design,
Stiffness,
Pressure,
Additive manufacturing,
Manufacturing,
Grippers
References
References
1.
Zhou
, X.
Majidi
, C.
O'Reilly
, O. M.
2015
, “Soft Hands: An Analysis of Some Gripping Mechanisms in Soft Robot Design
,” Int. J. Solids Struct.
, 64
, pp. 155
–165
.2.
Cha
, H. J.
Koh
, K. C.
Yi
, B. J.
2014
, “Stiffness Modeling of a Soft Finger
,” Int. J. Control, Autom. Syst.
, 12
(1
), pp. 111
–117
.3.
Nagase
, J. Y.
Wakimoto
, S.
Satoh
, T.
Saga
, N.
Suzumori
, K.
2011
, “Design of a Variable-Stiffness Robotic Hand Using Pneumatic Soft Rubber Actuators
,” Smart Mater. Struct.
, 20
(10
), p. 105015
.4.
Brown
, E.
Rodenberg
, N.
Amend
, J.
Mozeika
, A.
Steltz
, E.
Zakin
, M. R.
Jaeger
, H. M.
2010
, “Universal Robotic Gripper Based on the Jamming of Granular Material
,” Proc. Natl. Acad. Sci.
, 107
(44
), pp. 18809
–18814
.5.
Jiang
, A.
Aste
, T.
Dasgupta
, P.
Althoefer
, K.
Nanayakkara
, T.
2013
, “Granular Jamming Transitions for a Robotic Mechanism
,” AIP Conf. Proc.
1542
(1
), pp. 385
–388
.6.
Kim
, Y. J.
Cheng
, S.
Kim
, S.
Iagnemma
, K.
2013
, “A Novel Layer Jamming Mechanism With Tunable Stiffness Capability for Minimally Invasive Surgery
,” IEEE Trans. Rob.
, 29
(4
), pp. 1031
–1042
.7.
Majidi
, C.
Wood
, R. J.
2010
, “Tunable Elastic Stiffness With Microconfined Magnetorheological Domains at Low Magnetic Field
,” Appl. Phys. Lett.
, 97
(16
), p. 164104
.8.
Wang
, M.
Fei
, R.
1999
, “Improvement of Machining Stability Using a Tunable Stiffness Boring Bar Containing an Electrorheological Fluid
,” Smart Mater. Struct.
, 8
(4
), p. 511
.9.
Petit
, F.
Friedl
, W.
Hoppner
, H.
Grebenstein
, M.
2015
, “Analysis and Synthesis of the Bidirectional Antagonistic Variable Stiffness Mechanism
,” IEEE/ASME Trans. Mechatronics
, 20
(2
), pp. 684
–695
.10.
Henke
, M.
Sorber
, J.
Gerlach
, G.
2013
, “EAP-Actuators With Improved Actuation Capabilities for Construction Elements With Controllable Stiffness
,” Adv. Sci. Technol.
, 79
, pp. 75
–80
.11.
Clark
, W. W.
Brigham
, J. C.
Mo
, C.
Joshi
, S.
2010
, “Modeling of a High-Deformation Shape Memory Polymer Locking Link
,” Proc. SPIE
, 7645
, p. 764507
.12.
Shan
, W.
Lu
, T.
Majidi
, C.
2013
, “Soft-Matter Composites With Electrically Tunable Elastic Rigidity
,” Smart Mater. Struct.
, 22
(8
), p. 085005
.13.
Schubert
, B. E.
Floreano
, D.
2013
, “Variable Stiffness Material Based on Rigid Low-Melting-Point-Alloy Microstructures Embedded in Soft Poly (Dimethylsiloxane)(PDMS)
,” RSC Adv.
, 3
(46
), pp. 24671
–24679
.14.
Behl
, M.
Lendlein
, A.
2007
, “Shape-Memory Polymers
,” Mater. Today
, 10
(4
), pp. 20
–28
.15.
Takashima
, K.
Zhang
, N.
Mukai
, T.
Guo
, S.
2010
, “Fundamental Study of a Position-Keeping Module Using a Shape-Memory Polymer
,” J. Rob. Soc. Jpn.
, 28
(7
), pp. 905
–912
.16.
Liu
, C.
Qin
, H.
Mather
, P. T.
2007
, “Review of Progress in Shape-Memory Polymers
,” J. Mater. Chem.
, 17
(16
), pp. 1543
–1558
.17.
Takashima
, K.
Sugitani
, K.
Morimoto
, N.
Sakaguchi
, S.
Noritsugu
, T.
Mukai
, T.
2014
, “Pneumatic Artificial Rubber Muscle Using Shape-Memory Polymer Sheet With Embedded Electrical Heating Wire
,” Smart Mater. Struct.
, 23
(12
), p. 125005
.18.
Koerner
, H.
Price
, G.
Pearce
, N. A.
Alexander
, M.
Vaia
, R. A.
2004
, “Remotely Actuated Polymer Nanocomposites—Stress-Recovery of Carbon-Nanotube-Filled Thermoplastic Elastomers
,” Nat. Mater.
, 3
(2
), pp. 115
–120
.19.
Leng
, J.
Wu
, X.
Liu
, Y.
2009
, “Infrared Light-Active Shape Memory Polymer Filled With Nanocarbon Particles
,” J. Appl. Polym. Sci.
, 114
(4
), pp. 2455
–2460
.20.
Cho
, J. W.
Kim
, J. W.
Jung
, Y. C.
Goo
, N. S.
2005
, “Electroactive Shape-Memory Polyurethane Composites Incorporating Carbon Nanotubes
,” Macromol. Rapid Commun.
, 26
(5
), pp. 412
–416
.21.
Schmidt
, A. M.
2006
, “Electromagnetic Activation of Shape Memory Polymer Networks Containing Magnetic Nanoparticles
,” Macromol. Rapid Commun.
, 27
(14
), pp. 1168
–1172
.22.
Yang
, Y.
Chen
, Y. H.
Wei
, Y.
Li
, Y. T.
2015
, “3D Printing of Shape Memory Polymer for Functional Part Fabrication
,” Int. J. Adv. Manuf. Technol.
, 84
(9
), pp. 2079
–2095
.23.
McEvoy
, M. A.
Correll
, N.
2014
, “Thermoplastic Variable Stiffness Composites With Embedded, Networked Sensing, Actuation, and Control
,” J. Compos. Mater.
, 49
(15
), pp. 1799
–1808
.24.
Shan
, W.
Diller
, S.
Tutcuoglu
, A.
Majidi
, C.
2015
, “Rigidity-Tuning Conductive Elastomer
,” Smart Mater. Struct.
, 24
(6
), p. 065001
.25.
Rousseau
, I. A.
2008
, “Challenges of Shape Memory Polymers: A Review of the Progress Toward Overcoming SMP's Limitations
,” Polym. Eng. Sci.
, 48
(11
), p. 2075
.26.
Mattar
, E.
2013
, “A Survey of Bio-Inspired Robotics Hands Implementation: New Directions in Dexterous Manipulation
,” Rob. Auton. Syst.
, 61
(5
), pp. 517
–544
.27.
Galloway
, K. C.
Polygerinos
, P.
Walsh
, C. J.
Wood
, R. J.
2013
, “Mechanically Programmable Bend Radius for Fiber-Reinforced Soft Actuators
,” 16th International Conference on Advanced Robotics
(ICAR
), Montevideo, Uruguay, Nov. 25–29, pp. 1
–6
.28.
Polygerinos
, P.
Wang
, Z.
Galloway
, K. C.
Wood
, R. J.
Walsh
, C. J.
2015
, “Soft Robotic Glove for Combined Assistance and At-Home Rehabilitation
,” Rob. Auton. Syst.
, 73
, pp. 135
–143
.29.
Jonsson
, U.
Lindahl
, O.
Andersson
, B.
2014
, “Modeling the High-Frequency Complex Modulus of Silicone Rubber Using Standing Lamb Waves and an Inverse Finite Element Method
,” IEEE Trans. Ultrason., Ferroelectr., Freq. Control
, 61
(12
), pp. 2106
–2120
.30.
Eskandari
, H.
Salcudean
, S. E.
Rohling
, R.
Ohayon
, J.
2008
, “Viscoelastic Characterization of Soft Tissue From Dynamic Finite Element Models
,” Phys. Med. Biol.
, 53
(22
), p. 6569
.31.
Udupa
, G.
Sreedharan
, P.
Dinesh
, P. S.
Kim
, D.
2014
, “Asymmetric Bellow Flexible Pneumatic Actuator for Miniature Robotic Soft Gripper
,” J. Rob.
, 2014
, p. 902625
.32.
Firouzeh
, A.
Salerno
, M.
Paik
, J.
2015
, “Soft Pneumatic Actuator With Adjustable Stiffness Layers for Multi-DoF Actuation
,” 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems
(IROS
), Hamburg, Germany, Sept. 28–Oct. 2, pp. 1117
–1124
.33.
Udupa
, G.
Sreedharan
, P.
Aditya
, K.
2010
, “Robotic Gripper Driven by Flexible Microactuator Based on an Innovative Technique
,” IEEE Workshop on Advanced Robotics and Its Social Impacts
(ARSO
), Seoul, Korea, Oct. 6–28, pp. 111
–116
.34.
Tobushi
, H.
Okumura
, K.
Hayashi
, S.
Ito
, N.
2001
, “Thermomechanical Constitutive Model of Shape Memory Polymer
,” Mech. Mater.
, 33
(10
), pp. 545
–554
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