Enhancement of EAP actuated facial expressions by designed chamber geometry in elastomers

In this paper, the authors explore various ways that designed chambering of elastomers can enhance electroactive polymer (EAP) actuation. Such enhancements include structuring of chambers for various mechanical functions and advantages, boosting of surface area of a polymer for enhanced ionic migration, construction of advanced electret foams for sensing and for tunable hydrophobicity for micro/pumping action, and distribution of composite EAP devices throughout the chambered elastomer to achieve discrete controllability of electroactive polymer actuators. The authors also discuss the chambering of EAP materials themselves for enhanced actuation effects. With varied design of the chambers of the elastomer, the mechanical and structural properties of the elastomer can be tuned to greatly enhance EAP actuation. The chambers can be designed in accordion-like bellows to achieve extreme elongation with low forces, in spiral geometries to effect negative or neutral poisson's ratio under actuation, and with embedded fluidic bellows for fluidic actuation or sensing. These are but a few examples of the advantages that can be achieved via designed chambering of elastomers. The authors also discuss various application uses of the described chambering technologies. Such chambered elastomers, combined with advanced muscle-like actuators, can substantially benefit facelike robots (useful for entertainment and education etc), prosthetics, and numerous modalities of bio-inspired locomotion. In the efforts of the authors to generate facial expression robots with low-power lightweight actuators is described.