Mechanical characterization of a dielectric elastomer microactuator with ion-implanted electrodes

We report on the mechanical characterization and modeling of a non-prestretched dielectric elastomer diaphragm microactuator with ion-implanted electrodes under the influence of a distributed load (pressure). Thin polydimethysiloxane (PDMS) membranes (30 mu m thick, 2-3 mm diameter) were implanted on both side with gold ions by Filtered Cathodic Vacuum Arc (FCVA) and bonded on silicon chips with through-holes. A voltage applied between the implanted electrodes creates a compressive stress in the dielectric and causes the membrane to buckle and form a bump whose height depends on the mechanical properties of the electroactive compound, the voltage and the force applied on the membrane. Maximum unloaded displacements up to 7% of the membrane's lateral dimensions were achieved, which was reduced to 3% when a distributed force of I kPa was applied on the membrane. The maximum mechanical work obtained by the actuators is in the range of 0.3 mu J. An analytical model was developed to calculate the displacement of the Dielectric Elastomer Actuators (DEAs) based on their mechanical and geometrical properties, voltage and applied force. The model shows very good agreement with the measurements and allows accurate performance prediction and dimensioning of such actuators. (C) 2008 Elsevier B.V. All rights reserved.