Buckling of Dielectric Elastomeric Plates for Soft, Microfluidic Pumps
Behrouz Tavakol (Virginia Tech), Michael Bozlar (Princeton University), Guillaume Froehlicher (Princeton University), Howard Stone (Princeton University), Ilhan Aksay (Princeton University), Douglas Holmes (Virginia Tech)
Soft Materials and Structures
Mon 4:20 - 5:40
Barus-Holley 158
Buckling of plates and rods are often avoided in design of structures; however, proper implementation of these instabilities lead to advanced material functionality. In this work, we use the buckling of circular plates for pumping fluids with a specific flow rate. Dielectric elastomers have been widely used in many applications such as soft robotics, opto-electro-mechanical systems, and energy harvesting devices due to their unique mechanical and electrical properties as well as their ability to convert electrical signals to mechanical actuations and vice versa. If we confine a thin dielectric elastomeric plate at its edge and expose it to an electric field, it will undergo buckling. When embedded within a microfluidic device, the out-of-plane deformation can be used as a pumping mechanism to inject the fluids above or below the plate into channels. In order for the device to be compatible with fluids, the dielectric film was sandwiched between two thin, flexible, solid electrodes that can not only be in direct contact with fluids, but also undergo significant deformation without losing their functionality. We conducted experiments to quantify the voltage-induced buckling instability and measured the flow rate as a function of voltage. In addition, the effect of other boundary conditions such as volume and pressure difference between two sides of the thin film was investigated. We also show that these pumps can be used in series and/or parallel to enhance the flow rate besides the pump efficiency. Finally, we offer an analytical prediction that uses plate buckling theory to estimate the critical voltage for buckling of confined dielectric plates.