Scalable Electroactive Polymer for Variable Stiffness Suspensions

We present an approach for creating a reliable variable stiffness suspension using prestretched electroactive polymer films. In comparison to other variable-stiffness devices, the design is compact, lightweight, consumes low energy, and can change its stiffness in approximately 10 ms. Attention to the main causes of failure increases the reliability of the device so that multiple layers can be combined for increased loads and stiffness. A device with 20 layers supports loads of over 15 N at minimum stiffness and maximum voltage for displacements of ±7 mm and up to 138 N at maximum stiffness with a displacement of 20 mm. Multilayer devices have demonstrated 3 million mechanical load cycles and hundreds of thousands of stiffness variation (charging and discharging) cycles, respectively.