Multilayer Dielectric Elastomer Actuator with Enhanced Breakdown Strength via Regulating the Layer Thickness Ratio

Area of Science:

• Materials Science
• Polymer Science
• Actuator Technology

Background:

• Dielectric elastomers offer rapid response, large strain, and high energy density for flexible actuators.
• Improving breakdown strength is key for actuator stability and higher strain at increased voltages.

Purpose of the Study:

• To investigate bilayer electric field redistribution theory for designing multilayer dielectric elastomers.
• To enhance the breakdown strength and actuation performance of dielectric elastomer actuators.

Main Methods:

• Fabrication of 11-layer (MWCNT-Ecoflex)/Ecoflex composites with varying insulating/polarization layer thickness ratios (r).
• Theoretical and experimental analysis of electric field redistribution in multilayer structures.
• Characterization of breakdown strength and actuated strain under varying electric fields.

Main Results:

• Increasing the layer thickness ratio (r) between low-dielectric (Ecoflex) and high-dielectric (MWCNT-Ecoflex) layers enhances breakdown strength.
• Composites with a layer thickness ratio of 3.31 achieved an actuated strain of 22.79% at 13.6 MV m⁻¹.
• Demonstrated a direct correlation between layer thickness ratio and improved dielectric elastomer performance.

Conclusions:

• The study successfully guided the structural design of multilayer dielectric elastomers through electric field redistribution theory.
• Tailoring the thickness ratio of insulating and polarization layers is an effective strategy to enhance breakdown strength.
• Optimized dielectric elastomers show significant potential for high-performance flexible actuator applications.