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Bar-Cohen : Biomimetics: Biologically Inspired Technologies DK3163_c010 Final Proof page 267 21.9.2005 11:46am

10

Artificial Muscles Using
Electroactive Polymers

Yoseph Bar-Cohen

CONTENTS
10.1 Introduction ........................................................................................................................................ 267
10.2 History and Currently Available Active Polymers............................................................................ 268
10.3 Types of Electroactive Polymers ....................................................................................................... 270
10.3.1 Electronic EAP .................................................................................................................... 270
10.3.1.1 Dielectric Elastomer EAP.................................................................................... 270
10.3.1.2 Ferroelectric Polymers......................................................................................... 271
10.3.1.3 Electrostrictive Graft Elastomers ........................................................................ 272
10.3.1.4 Electrostrictive Paper........................................................................................... 273
10.3.2 Ionic EAP............................................................................................................................. 273
10.3.2.1 Ionic Polymer Gels .............................................................................................. 273
10.3.2.2 Ionomeric Polymer–Metal Composites............................................................... 274
10.3.2.3 Conductive Polymers........................................................................................... 274
10.3.2.4 Carbon Nanotubes................................................................................................ 276
10.4 EAP Characterization......................................................................................................................... 276
10.5 Applications of EAP........................................................................................................................... 276
10.5.1 Artificial Organs and Other Medical Applications ............................................................. 277
10.5.2 EAP-Actuated Biomimetic Robots...................................................................................... 279
10.5.2.1 Gripper and Robotic Arm Lifter.......................................................................... 280
10.5.2.2 Biologically Inspired Robots for Planetary Robotics.......................................... 280
10.6 Milestone for the Field....................................................................................................................... 282
10.7 Summary and Outlook........................................................................................................................ 286
Acknowledgment............................................................................................................................................ 287
References....................................................................................................................................................... 287

10.1 INTRODUCTION

Natural muscles are one of the most important actuators in biological systems larger than a
bacterium. They are highly optimized since they are fundamentally driven by the same mechanism
in all animals and the difference between species is relatively small. The drive mechanism of
muscles is complex and they are capable of lifting large loads with short time response in the range
of milliseconds. Human made actuators that most closely emulate muscles are the recently emerged

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