Research Papers

Design and Fabrication of a Soft Robotic Hand With Embedded Actuators and Sensors

[+] Author and Article Information
Yu She

Department of Mechanical and
Aerospace Engineering,
The Ohio State University,
Columbus, OH 43210
e-mail: she.22@osu.edu

Chang Li

Department of Mechanical Engineering,
Tsinghua University,
Beijing 100084, China
e-mail: lichang427@sina.com

Jonathon Cleary

Department of Mechanical and
Aerospace Engineering,
The Ohio State University,
Columbus, OH 43210
e-mail: cleary.77@osu.edu

Hai-Jun Su

Department of Mechanical and
Aerospace Engineering,
The Ohio State University,
Columbus, OH 43210
e-mail: su.298@osu.edu

1Corresponding author.

Manuscript received August 17, 2014; final manuscript received December 23, 2014; published online February 27, 2015. Assoc. Editor: Aaron M. Dollar.

J. Mechanisms Robotics 7(2), 021007 (May 01, 2015) (9 pages) Paper No: JMR-14-1224; doi: 10.1115/1.4029497 History: Received August 17, 2014; Revised December 23, 2014; Online February 27, 2015

This paper details the design and fabrication process of a fully integrated soft humanoid robotic hand with five finger that integrate an embedded shape memory alloy (SMA) actuator and a piezoelectric transducer (PZT) flexure sensor. Several challenges including precise control of the SMA actuator, improving power efficiency, and reducing actuation current and response time have been addressed. First, a Ni-Ti SMA strip is pretrained to a circular shape. Second, it is wrapped with a Ni-Cr resistance wire that is coated with thermally conductive and electrically isolating material. This design significantly reduces actuation current, improves circuit efficiency, and hence reduces response time and increases power efficiency. Third, an antagonistic SMA strip is used to improve the shape recovery rate. Fourth, the SMA actuator, the recovery SMA strip, and a flexure sensor are inserted into a 3D printed mold which is filled with silicon rubber materials. The flexure sensor feeds back the finger shape for precise control. Fifth, a demolding process yields a fully integrated multifunctional soft robotic finger. We also fabricated a hand assembled with five fingers and a palm. We measured its performance and specifications with experiments. We demonstrated its capability of grasping various kinds of regular or irregular objects. The soft robotic hand is very robust and has a large compliance, which makes it ideal for use in an unstructured environment. It is inherently safe to human operators as it can withstand large impacts and unintended contacts without causing any injury to human operators or damage to the environment.

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Trivedi, D., Rahn, C. D., Kier, W. M., and Walker, I. D., 2008, “Soft Robotics: Biological Inspiration, State of the Art, and Future Research,” Appl. Bionics Biomech., 5(3), pp. 99–117. [CrossRef]
Cho, K.-J., Koh, J.-S., Kim, S., Chu, W.-S., Hong, Y., and Ahn, S.-H., 2009, “Review of Manufacturing Processes for Soft Biomimetic Robots,” Int. J. Precis. Eng. Manuf., 10(3), pp. 171–181. [CrossRef]
Martinez, R. V., Glavan, A. C., Keplinger, C., Oyetibo, A. I., and Whitesides, G. M., 2014, “Soft Actuators and Robots That Are Resistant to Mechanical Damage,” Adv. Funct. Mater., 24(20), pp. 3003–3010. [CrossRef]
Mosadegh, B., Polygerinos, P., Keplinger, C., Wennstedt, S., Shepherd, R. F., Gupta, U., Shim, J., Bertoldi, K., Walsh, C. J., and Whitesides, G. M., 2014, “Pneumatic Networks for Soft Robotics That Actuate Rapidly,” Adv. Funct. Mater., 24(15), pp. 2163–2170. [CrossRef]
Shepherd, R. F., Ilievski, F., Choi, W., Morin, S. A., Stokes, A. A., Mazzeo, A. D., Chen, X., Wang, M., and Whitesides, G. M., 2011, “Multigait Soft Robot,” Proc. Natl. Acad. Sci. U.S.A., 108(51), pp. 20400–20403. [CrossRef] [PubMed]
Kim, S., Laschi, C., and Trimmer, B., 2013, “Soft Robotics: A Bioinspired Evolution in Robotics,” Trends Biotechnol., 31(5), pp. 287–294. [CrossRef] [PubMed]
Shepherd, R. F., Stokes, A. A., Freake, J., Barber, J., Snyder, P. W., Mazzeo, A. D., Cademartiri, L., Morin, S. A., and Whitesides, G. M., 2013, “Using Explosions to Power a Soft Robot,” Angew. Chem., 125(10), pp. 2964–2968. [CrossRef]
Park, Y.-L., Chen, B.-R., and Wood, R. J., 2012, “Design and Fabrication of Soft Artificial Skin Using Embedded Microchannels and Liquid Conductors,” IEEE Sens. J., 12(8), pp. 2711–2718. [CrossRef]
Renda, F., Cianchetti, M., Giorelli, M., Arienti, A., and Laschi, C., 2012, “A 3D Steady-State Model of a Tendon-Driven Continuum Soft Manipulator Inspired by the Octopus Arm,” Bioinspiration Biomimetics, 7(2), p. 025006. [CrossRef] [PubMed]
Ozawa, R., Hashirii, K., and Kobayashi, H., 2009, “Design and Control of Underactuated Tendon-Driven Mechanisms,” IEEE International Conference on Robotics and Automation (ICRA’09), Kobe, Japan, May 12–17, pp. 1522–1527 [CrossRef].
Mavroidis, C., 2002, “Development of Advanced Actuators Using Shape Memory Alloys and Electrorheological Fluids,” J. Res. Nondestr. Eval., 14(1), pp. 1–32. [CrossRef]
Seok, S., Onal, C. D., Cho, K.-J., Wood, R. J., Rus, D., and Kim, S., 2013, “Meshworm: A Peristaltic Soft Robot With Antagonistic Nickel Titanium Coil Actuators,” IEEE/ASME Trans. Mechatronics, 18(5), pp. 1485–1497. [CrossRef]
Icardi, U., 2001, “Large Bending Actuator Made With SMA Contractile Wires: Theory, Numerical Simulation and Experiments,” Composites, Part B, 32(3), pp. 259–267. [CrossRef]
Zhang, J.-J., Yin, Y.-H., and Zhu, J.-Y., 2013, “Electrical Resistivity-Based Study of Self-Sensing Properties for Shape Memory Alloy-Actuated Artificial Muscle,” Sensors, 13(10), pp. 12958–12974. [CrossRef] [PubMed]
Paik, J. K., and Wood, R. J., 2012, “A Bidirectional Shape Memory Alloy Folding Actuator,” Smart Mater. Struct., 21(6), p. 065013. [CrossRef]
Liu, S.-H., Huang, T.-S., and Yen, J.-Y., 2009, “Tracking Control of Shape-Memory-Alloy Actuators Based on Self-Sensing Feedback and Inverse Hysteresis Compensation,” Sensors, 10(1), pp. 112–127. [CrossRef] [PubMed]
Wang, T.-M., Shi, Z.-Y., Liu, D., Ma, C., and Zhang, Z.-H., 2012, “An Accurately Controlled Antagonistic Shape Memory Alloy Actuator With Self-Sensing,” Sensors, 12(6), pp. 7682–7700. [CrossRef] [PubMed]
Bergamasco, M., Salsedo, F., and Dario, P., 1989, “Shape Memory Alloy Micromotors for Direct-Drive Actuation of Dexterous Artificial Hands,” Sens. Actuators, 17(1), pp. 115–119. [CrossRef]
Lee, J. H., Okamoto, S., and Matsubara, S., 2012, “Development of Multi-Fingered Prosthetic Hand Using Shape Memory Alloy Type Artificial Muscle,” Comput. Technol. Appl., 3(7), pp. 477–484.
Hino, T., and Maeno, T., 2004, “Development of a Miniature Robot Finger With a Variable Stiffness Mechanism Using Shape Memory Alloy,” International Symposium on Robotics and Automation, Querétaro, México, Aug. 25–27.
Yang, K., and Gu, C., 2002, “A Novel Robot Hand With Embedded Shape Memory Alloy Actuators,” Proc. Inst. Mech. Eng., Part C, 216(7), pp. 737–745. [CrossRef]
Dilibal, S., Guner, E., and Akturk, N., 2002, “Three-Finger SMA Robot Hand and Its Practical Analysis,” Robotica, 20(2), pp. 175–180 [CrossRef].
Dollar, A. M., and Howe, R. D., 2007, “The SDM Hand as a Prosthetic Terminal Device: A Feasibility Study,” IEEE 10th International Conference on Rehabilitation Robotics (ICORR 2007), Noordwijk, The Netherlands, June 13–15, pp. 978–983 [CrossRef].
Dollar, A. M., and Howe, R. D., 2005, “Design and Evaluation of a Robust Compliant Grasper Using Shape Deposition Manufacturing,” ASME Paper No. IMECE2005-79791 [CrossRef].
Vogtmann, D. E., Gupta, S. K., and Bergbreiter, S., 2013, “Characterization and Modeling of Elastomeric Joints in Miniature Compliant Mechanisms,” ASME J. Mech. Rob., 5(4), p. 041017. [CrossRef]
Bejgerowski, W., Gerdes, J. W., Gupta, S. K., and Bruck, H. A., 2011, “Design and Fabrication of Miniature Compliant Hinges for Multi-Material Compliant Mechanisms,” Int. J. Adv. Manuf. Technol., 57(5–8), pp. 437–452. [CrossRef]
Dollar, A. M., Wagner, C. R., and Howe, R. D., 2006, “Embedded Sensors for Biomimetic Robotics Via Shape Deposition Manufacturing,” First IEEE/RAS-EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob 2006) [CrossRef], Pisa, Italy, Feb. 20–22, pp. 763–768.
Dollar, A. M., and Howe, R. D., 2006, “A Robust Compliant Grasper Via Shape Deposition Manufacturing,” IEEE/ASME Trans. Mechatronics, 11(2), pp. 154–161. [CrossRef]
Park, Y.-L., Chau, K., Black, R. J., and Cutkosky, M. R., 2007, “Force Sensing Robot Fingers Using Embedded Fiber Bragg Grating Sensors and Shape Deposition Manufacturing,” IEEE International Conference on Robotics and Automation (ICRA), Rome, Italy, Apr. 10–14, pp. 1510–1516 [CrossRef].
Deimel, R., and Brock, O., 2013, “A Compliant Hand Based on a Novel Pneumatic Actuator,” IEEE International Conference on Robotics and Automation (ICRA), Karlsruhe, Germany, May 6–10, pp. 2047–2053 [CrossRef].
Price, A., Jnifene, A., and Naguib, H., 2007, “Design and Control of a Shape Memory Alloy Based Dexterous Robot Hand,” Smart Mater. Struct., 16(4), pp. 1401–1414. [CrossRef]
DeLaurentis, K., Mavroidis, C., and Pfeiffer, C., 2000, “Development of a Shape Memory Alloy Actuated Robotic Hand,” 7th International Conference on New Actuators (ACTUATOR 2000), Bremen, Germany, June 19–21, pp. 281–285.
Farias, V., Solis, L., Meléndez, L., Garcia, C., and Velázquez, R., 2009, “A Four-Fingered Robot Hand With Shape Memory Alloys,” IEEE AFRICON (AFRICON’09), Nairobi, Kenya, Sept. 23–25 [CrossRef].


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Fig. 1

The conceptual design of the soft robotic hand

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Fig. 2

The actuation and shape recovery cycle of the SMA actuator: (a) initial position, (b) grasping position, and (c) releasing position

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Fig. 3

The schematic of the full integrated soft robotic finger

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Fig. 4

The overview of the fabrication process for the fully integrated robotic hand

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Fig. 5

Trained shape of the SMA strip

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Fig. 6

The coating and winding process of the SMA strip and the resistance wire

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Fig. 7

The 3D printed mold parts (left) and the complete assembled mold (right)

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Fig. 8

(a) The soft robotic finger body with various compliance. (b) The fabricated fully integrated soft robotic finger.

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Fig. 9

The bending process of the fully integrated soft robotic finger with an input current of 0.7 A at 7 V

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Fig. 10

The final radius of curvature ρ (mm) versus current I (A)

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Fig. 11

The response time to the full actuation t (s) versus the current I (A)

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Fig. 12

Comparison of the shape recovery process: without the recovery SMA actuator (circle) and with the recovery actuator (diamond)

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Fig. 13

Relation of resistance versus radius of the flexure sensor for forward and backward bending

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Fig. 14

PD control of the finger position with flexure sensor feedback

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Fig. 15

Grasping experiment of the assembled robot hand




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