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Long-lifetime All-polymer Artificial Muscle Transducers

Published online by Cambridge University Press:  01 February 2011

Roy Kornbluh
Affiliation:
roy.kornbluh@sri.com
Annjoe Wong-Foy
Affiliation:
annjoe.wongfoy@sri.com, SRI International, Menlo Park, United States
Ron Pelrine
Affiliation:
ron.pelrine@sri.com, SRI International, Menlo Park, United States
Harsha Prahlad
Affiliation:
harsha.prahlad@sri.com, SRI International, Menlo Park, United States
Brian McCoy
Affiliation:
roy.kornbluh@sri.com
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Abstract

The dielectric elastomer, a particularly attractive type of electroactive polymer, uses commercial polymers such as acrylic and silicone elastomers. The technology has been limited in application by perceived lifetime issues. By addressing several lifetime issues, lifetimes of more than one million cycles, and in some cases beyond ten million cycles, were achieved with a variety of transducer configurations (including operation in generator mode) under a variety of operating conditions (including high humidity). Dielectric elastomers can produce maximum actuation strains of more than 100% and specific energy density exceeding that of known electric-field induced technology. Performance testing for dielectric elastomer actuators has typically been for peak-performance or “over-driven” conditions with short operational lifetimes (typically 100s or 1000s of cycles), particularly under conditions such as high humidity. By minimizing electric field and mechanical strain concentration factors, long lifetimes (>1 million cycles) with acrylic transducers were achieved with actuation strains as great as 40% areal strain (and up to 100% areal strain in generator mode). Actuators in a dry environment had an almost 20x increase in lifetime over actuators at ambient humidity (about 50% RH) at the same driving field conditions. Long actuation lifetimes were also achieved in a 100% RH environment and when fully submerged in salt water at reduced operating strain and field. In 100% RH, lifetimes of several million cycles were achieved at 4% strain. In underwater operation, 6 out of 11 actuators survived for >10 million cycles with an electric field limited to 32 MV/m and approximately 2% strain. The demonstrated lifecycle improvements are applicable to a variety of uses of dielectric elastomers, including haptic interface devices, pumps (implantable and external), optical positioners, and “artificial muscles” to replace small damaged muscles. Continued improvements in materials, actuator design, and packaging, combined with management of operational conditions as described here, should support new practical application of this promising technology.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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References

REFERENCES

1 Pelrine, R., Introduction: history of dielectric elastomer actuators, Introduction in Carpi, F., DeRossi, D., Kornbluh, R., Pelrine, R., and Sommer-Larsen, P., Dielectric Elastomers as Electromechanical Transducers. Fundamentals, Materials, Devices, Models and Applications of an Emerging Electroactive Polymer Technology (Elsevier Press, Amsterdam, the Netherlands, 2008), pp. 270278.Google Scholar
2 Pelrine, R., Kornbluh, R., Pei, Q., and Joseph, J.. High-speed electrically actuated elastomers with over 100% strain, Science 287 (5454), 836839 (2000).Google Scholar
3 Zakrevskii, V.A., Sudar, N.T., Zaopo, A., and Dubitsky, Y.A., Mechanism of electrical degradation and breakdown of insulating polymers, J. Appl. Phys. 93, 2135 (2003).Google Scholar
4 Zhao, X. and Suo, Z., Method to analyze electromechanical stability of dielectric elastomers, Appl. Phys. Lett. 91, 061921 (2007).Google Scholar
5 Plante, J S. and Dubowsky, S., Large-scale failure modes of dielectric elastomer actuators, Int. J. Solids Struct. 43, 7727–51 (2006).Google Scholar
6 Lam, T., Tran, H., Yuan, W., Yu, Z., Ha, S.M., Kaner, R., and Pei, Q., Polyaniline nanofibers as a novel electrode material for fault-tolerant dielectric elastomer actuators, Proc. SPIE 6927, 69270O–4 (2008).Google Scholar
7 Plante, J. and Dubowsky, S., Binary actuation, Chapter 26 in Carpi, F., DeRossi, D., Kornbluh, R., Pelrine, R., and Sommer-Larsen, P., Dielectric Elastomers as Electromechanical Transducers. Fundamentals, Materials, Devices, Models and Applications of an Emerging Electroactive Polymer Technology (Elsevier Press, Amsterdam, the Netherlands, 2008), pp. 270278.Google Scholar
8 Babic, M., Vertechy, R., Berselli, G., Lenarcic, J., Castelli, V. Parenti, and Vassura, G., An electronic driver for improving the open and closed loop electro-mechanical response of dielectric elastomer actuators, Mechatronics 20 (2), 201212 (2010).Google Scholar
9 Kornbluh, R. and Pelrine, R., High-performance acrylic and silicone elastomers, Chapter 4 in Carpi, F., DeRossi, D., Kornbluh, R., Pelrine, R., and Sommer-Larsen, P., Dielectric Elastomers as Electromechanical Transducers. Fundamentals, Materials, Devices, Models and Applications of an Emerging Electroactive Polymer Technology (Elsevier Press, Amsterdam, the Netherlands, 2008), pp. 3342.Google Scholar
10 Rosenthal, Marcus, personal communication, March 2010.Google Scholar
11 Thomsen, B. and Tryson, M., Highly accelerated stress testing (HAST) of DEAP actuators, Proc. SPIE 7287, 102113 (2009).Google Scholar
12 Pelrine, R., Kornbluh, R., and Joseph, J., Electrostriction of polymer dielectrics with compliant electrodes as a means of actuation, Sensor. Actuat. A-Phys. 64, 7485 (1998).Google Scholar
13 Brochu, P. and Pei, Q., Advances in dielectric elastomers for actuators and artificial muscles, Macromol. Rapid Commun. 31, 1036 (2010).Google Scholar
14 Kornbluh, R., Pelrine, R., Pei, Q., Rosenthal, M., Stanford, S., Bonwit, N., Heydt, R., Prahlad, H., and Shastri, S., Application of dielectric elastomer EAP actuators, Chapter 16 in Electroactive Polymer (EAP) Actuators as Artificial Muscles: Reality, Potential and Challenges, edited by Bar-Cohen, Y., 2nd edition (SPIE Press, Bellingham, Washington, 2004), pp. 529589.Google Scholar
15 Kofold, G., The static actuation of dielectric elastomer actuators: how does pre-stretch improve actuation? J. Phys. D: Appl. Phys. 41 (1), 11 (2008).Google Scholar
16 Bauer, S. and Paajanen, M., Electromechanical characterization and measurement protocol for dielectric elastomer actuators. Smart structures and materials 2006: electroactive polymer actuators and devices (EAPAD), Proc. SPIE 6168, 698706 (2006).Google Scholar
17 Suo, Z., Zhao, X. and Greene, W.H., A nonlinear field theory of deformable dielectrics, J. Mech. Phys. Solids, 56, 467–286 (2008).Google Scholar
18 Wissler, M. and Mazza, E., Electromechanical coupling in dielectric elastomer actuators, Sensor. Actuat. A-Phys. 138 (2), 384393 (2007).Google Scholar
19 Pelrine, R., Kornbluh, R., Eckerle, J., Jeuck, P., Oh, S., Pei, Q., and Stanford, S., Dielectric elastomers: generator mode fundamentals and applications, in Proc. SPIE 4329, 148156 (2001).Google Scholar
20 Kornbluh, R., Fundamental configurations for dielectric elastomer actuators, Chapter 8 in Carpi, F., DeRossi, D., Kornbluh, R., Pelrine, R., and Sommer-Larsen, P., Dielectric Elastomers as Electromechanical Transducers. Fundamentals, Materials, Devices, Models and Applications of an Emerging Electroactive Polymer Technology (Elsevier Press, Amsterdam, the Netherlands, 2008), pp. 7990.Google Scholar
21 Pei, Q., Pelrine, R., Stanford, S., Kornbluh, R., and Rosenthal, M., Electroelastomer rolls and their application for biomimetic walking robots, Synth. Metal, 135–136 (129), 131 (2003).Google Scholar
22 Pei, Q., Stanford, S., Rosenthal, M., Pelrine, R., Kornbluh, R., Meijer, K., and Full, R., 3-D multifunctional electroelastomer actuators and their application for biomimetic walking robots, Proc. SPIE 4698, 246253 (2002).Google Scholar
23 Prahlad, H., Pelrine, R., and Kornbluh, R., Guggenberg, P. von, Chhokar, S., and Eckerle, J., Programmable surface deformation: Thickness-mode electroactive polymer actuators and their applications, Proc. SPIE 5759, 102113 (2005).Google Scholar