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TitleElectric field around a dielectric elastomer actuator in proximity to the human body
Publication TypeConference Paper
Year of Publication2008
AuthorsMcKenzie, A.C., Calius E.P., and Anderson I.A.
Conference NameProceedings of SPIE - The International Society for Optical Engineering
Date Published2008
KeywordsActuators, Dielectric devices, Dielectric Elastomer Actuators (DEA), Elastomers, Electric field effects, Fringe fields, MATHEMATICAL MODELS, Stacked actuators
AbstractDielectric elastomer actuators (DEAs) are a promising artificial muscle technology that will enable new kinds of prostheses and wearable rehabilitation devices. DEAs are driven by electric fields in the MV/m range and the dielectric elastomer itself is typically 3Oμm in thickness or more. Large operating voltages, in the order of several kilovolts, are then required to produce useful strains and these large voltages and the resulting electric fields could potentially pose problems when DEAs are used in close proximity to the human body. The fringing electric fields of a DEA in close association with the skin were modelled using finite element methods. The model was verified against a known analytic solution describing the electric field surrounding a capacitor in air. The agreement between the two is good, as the difference is less than 10% unless within 4.5mm of the DEAós lateral edges. As expected, it was found that for a DEA constructed with thinner dielectric layers, the fringe field strength dropped in direct proportion to the reduction in applied voltage, despite the internal field being maintained at the same level. More interestingly, modelling the electric field around stacked DEAs showed that for an even number of layers the electric field is an order of magnitude less than for an odd number of layers, due to the cancelling of opposing electric fields.

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