Abstract Dielectric elastomer actuators (DEAs) are an emerging type of soft actuator that show many advantages including large actuation strains, high energy density and high theoretical efficiency. Due to the inherent elasticity, such actuators can also be used as soft oscillators and, when at resonance, the dielectric elastomer oscillators (DEOs) can exhibit a peak oscillation amplitude and power output with an improved energy efficiency in comparison to non-resonant behaviour. However, most existing DEOs have a fixed pre-defined morphology and demonstrate a single stable equilibrium, which limits their versatility. In this work, a conical DEO is proposed which may exhibit either monostability (i.e. one stable equilibrium point) or bistability (two equilibria). The system demonstrates a transition between two regimes using a voltage control. Such a feature allows the DEO system to have multiple oscillation modes with different equilibrium points and the transition between equilibria is controlled by an effective control strategy proposed in this work. A mathematical model based on the Euler-Lagrange method is developed to investigate the stability of this system and its complex nonlinear dynamic response in unforced and parametrically forced cases. This design has potential in more advanced and versatile DEO applications such as active vibrational controllers/ shakers, active morphing structures, smart energy harvesting and highly programmable robotic locomotion.

中文翻译：

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具有可切换单稳态到双稳态的锥形介电弹性体振荡器的非线性动力学

摘要 介电弹性体驱动器（DEA）是一种新兴的软驱动器，具有驱动应变大、能量密度高和理论效率高等诸多优点。由于固有的弹性，这种致动器也可以用作软振荡器，并且在共振时，介电弹性体振荡器 (DEO) 可以表现出峰值振荡幅度和功率输出，与非共振行为相比，能量效率更高。然而，大多数现有的 DEO 具有固定的预定义形态，并表现出单一的稳定平衡，这限制了它们的多功能性。在这项工作中，提出了一种锥形 DEO，它可能表现出单稳态（即一个稳定的平衡点）或双稳态（两个平衡）。该系统使用电压控制演示了两种状态之间的转换。这样的特征允许 DEO 系统具有具有不同平衡点的多种振荡模式，并且平衡之间的转变由本工作中提出的有效控制策略控制。建立了基于欧拉-拉格朗日方法的数学模型，以研究该系统在非受力和参数受力情况下的稳定性及其复杂的非线性动态响应。这种设计在更先进和更通用的 DEO 应用中具有潜力，例如主动振动控制器/振动器、主动变形结构、智能能量收集和高度可编程的机器人运动。建立了基于欧拉-拉格朗日方法的数学模型，以研究该系统在非受力和参数受力情况下的稳定性及其复杂的非线性动态响应。这种设计在更先进和更通用的 DEO 应用中具有潜力，例如主动振动控制器/振动器、主动变形结构、智能能量收集和高度可编程的机器人运动。建立了基于欧拉-拉格朗日方法的数学模型，以研究该系统在非受力和参数受力情况下的稳定性及其复杂的非线性动态响应。这种设计在更先进和更通用的 DEO 应用中具有潜力，例如主动振动控制器/振动器、主动变形结构、智能能量收集和高度可编程的机器人运动。