Mechanical properties of electroactive polymer microactuators with ion-implanted electrodes

Samuel Rosset, Muhamed Niklaus, Philippe Dubois, Massoud Dadras, Herbert R. Shea, Yoseph Bar-Cohen
2007 Electroactive Polymer Actuators and Devices (EAPAD) 2007  
We report on the use of the bulge test method to characterize the mechanical properties of miniaturized bucklingmode dielectric elastomer actuators (DEA). Our actuator consists of a Polydimethylsiloxane (PDMS) membrane bonded to a silicon chip with through holes. Compliant electrodes are fabricated on both sides of the membrane by metal ion implantation. The membrane buckles when a critical voltage is applied to the electrodes. The maximum displacements as well as the efficiency of such
more » ... s strongly depend on the mechanical parameters of the combined electrode-elastomer-electrode layer, mainly effective Young's modulus E and residual stress σ. We report measured E and σ obtained from bulge tests on PDMS membranes for two PDMS brands and for several different curing methods, which allows tuning the residual stress by controlling the rate of solvent evaporation. Bulge test measurements were then used to study the change in membranes' mechanical properties due to titanium ion implantation, compared to the properties obtained from depositing an 8 nm thick gold electrode. At the doses required to create a conductive layer, we find that the Ti ion implantation has a low impact on the membrane's overall rigidity (doubling of the Young's modulus and reducing the tensile stress) compared to the Au film (400% increase in E). The ion implantation method is an excellent candidate for DEAs' electrodes, which need to be compliant in order to achieve large displacements.
doi:10.1117/12.714944 fatcat:2m2h3nvb3ngtflho2hee3xhj5u