Ceramic Siloxane Composite as a Future Elastomer Dielectric for Micro-Actuator Realization

Polymer materials have been proposed to be good candidates for the development of new actuators. Due to their tunable mechanical and electrical properties, they can be used as electro-active devices. In this contribution, we focus on dielectric elastomers based actuators, and word toward establishing innovative and alternative integration/miniaturization processes inspired from microelectronics and MEMS technology. Dielectric elastomer actuators are made of an elastomer dielectric layer sandwiched between two conductive electrodes. Upon voltage application attraction forces between the electrodes generates a mechanical displacement correlated with the elastomer Young modulus and permittivity. Here, we propose to use the polydimethylesiloxane (PDMS) due to its high elasticity and its permittivity made adjustable by addition of ceramic nanoparticles. An original process for structuring PDMS layers is developed to overcome the technological challenges encountered during the integration of such materials in a micro-actuator. In this paper, we present several results of characterization that allowed us to better understand the physicochemical mechanisms involved at different technological steps for both the material alone or mixed with Titanate of Barium (TiO₃Ba) nanoparticles. We also measured the permittivity and the elasticity modulus of these materials at the end of the manufacturing process thereby verifying the conservation and the enhancement of the initial properties that set our choice. These results are very promising for increasing the electrostatic pressure or to lower the actuation voltage. To make a prediction of permittivity by a mixing rule, we inspect some theories in this aim. Finally, we demonstrate that the actuation response of charged elastomer with TiO₃Ba nanoparticles follows a hyperelastic behavior. This result is particularly helpful for the design of a micro-actuator in a given application.