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Dielectric elastomer actuators (DEAs) are increasingly recognized as pivotal components in flexible robotic actuators due to their substantial displacement, high energy density, rapid response times, and adaptable design characteristics. Nonetheless, the widespread adoption of DEAs is impeded by challenges such as elevated manufacturing costs and inherent nonlinear characteristics, which obscure a comprehensive understanding of the interplay between dielectric elastomer (DE) related material properties and voltage stimuli governing DEA operation. This study introduces a sophisticated finite element model that integrates Maxwell stress principles with the hyperelastic behavior inherent in DEs, enabling the numerical elucidation of DEA gripper dynamics. Utilizing this model, the minimum energy structure of DEs and their nonlinear actuation behavior under diverse electric field conditions are analyzed. The model's efficacy is validated through a meticulous comparison of simulated angular deflection and displacement with experimental results obtained from a six-segment DEA gripper across varying electric field intensities. Additionally, the impact of dielectric coefficients on the electro-actuated deformation of the DEA gripper is rigorously assessed, revealing a noteworthy enhancement in electro-actuation efficiency with increasing dielectric constants, particularly under high electric field conditions. Furthermore, the deformation differences of multi-segment DEA grippers under different voltage control strategies were investigated. The causes of these differences are discussed through stress analysis, and a sequential voltage application strategy is designed to optimize the gripping effect. The insights gleaned from this study offer valuable guidance for the design and optimization of DEAs tailored to diverse deformation requirements within the field of flexible robotic actuators. [ABSTRACT FROM AUTHOR]

The effects of hydrostatic pressure and modulus softening on electrode curvature and stress in a bilayer electrode plate are studied. It is found the hydrostatic pressure facilitates Li-ion diffusion. Modulus softening can weaken the stress assisted diffusion, promote the electrode to bend and reduce the stress. The electrode would nearly reach a lock-up state of deformation in the late charging process for potentiostatic charging, but the electrode bends continuously for galvanostatic charging. It is also found the electrode curvature firstly increases, and then reduces as current collector thickness increases, but decreases continuously by increasing the modulus of current collector. The thicker current collector and higher rigidity of current collector can block Li-ion diffusion for potentiostatic charging. Finally, the optimized charging procedure for reducing the bending deformation is galvanostatic first followed by potentiostatic, the current collector should be as thin and soft as possible when its own strength and role are satisfied. [ABSTRACT FROM AUTHOR]

[Display omitted] Diffusion-induced stress (DIS) generation in the microstructure and contact loss at the active material (AM)/solid electrolyte (SE) and active layer/current collector interfaces strongly affect the electrochemical and mechanical stabilities of all-solid-state batteries (ASSBs). A fully coupled chemo-mechanical model based on the 3D microstructure of ASSBs reconstructed via synchrotron transmission X-ray microscopy tomography was established to analyze the voltage profile of different Young's modulus matching factors for AM and SE, singular DIS generation, and interfacial failure in ASSBs. The working voltage plateau of the ASSBs increases with the Young's modulus of the SE, while the voltage oscillation at the beginning of the delithiation process was attributed to the chemical potential difference between the various points of the active particles. Stress and deformation are key factors affecting the interfacial stability of ASSBs. A singular stress field, in which strain localization preferentially occurs in AM particles, results in complex interfacial failures in ASSBs. Theoretical considerations suggest that an interlayer combining high interfacial toughness with a sufficient electron transport coefficient will prevent the delamination of ASSBs by making strain localization away from the current collector. The established model explains the electrochemo-mechanical behavior in response to different mechanical properties of AM and SE and the interfacial failure mechanism of ASSBs, which in turn will offer guidance in the design of future ASSBs. [ABSTRACT FROM AUTHOR]