Multistage Multistable Actuation System with scalable stroke, range and force capability based on cooperative electrostatic actuators (MUST ACT)

在电极之间非常小的距离处，静电致动器提供高能量密度和力。然而，在这些条件下，由于拉入，致动范围非常有限。对于传感器应用（陀螺仪：主振荡驱动，加速度计：力反馈），这些限制并不重要，因为几乎无质量的系统只需要非常低的驱动范围（µm）和非常低的力（µN）。然而，作为现有技术，静电致动不能用于“宏”应用所需的大范围和力。 现有技术是通过两个夹紧致动器与“移动”致动器的协作功能来提供大行程和力的英寸蜗杆马达。然而，这些致动器系统相对较大（最小多层芯片ca.该项目的动机是研究实现静电驱动的尺蠖状致动器系统的科学基础，该致动器系统基于大量的合作静电致动器，这些致动器是小型化的，可以通过标准Si技术制造，并且提供大行程（cm）和大力（N）。对于最后的愿景，需要更好地理解基于微系统的致动器系统的原理、限制和边界条件，该致动器系统由大量的小型化、多级、多稳态和合作的静电致动器构建，并且提供可缩放的步长、总范围和力，这些都可以在几个数量级上缩放。一个具体的科学问题是非线性静电力的影响，对机械稳定性的每个单一的，分布式多稳态和合作的子致动器和总的致动器系统的耦合。这里的基本问题是有多少这些合作和级联的单个致动器可以集成为一个仍然稳定的总系统，以及什么是小型化，精度和可控性的限制（例如，由粗糙度和几何偏差制造的所有致动器内的元件）。另外，需要对由每个静电致动器（在空闲和活动状态下）提供的固有电容感测的限制和交叉耦合进行系统调查。此外，需要了解使用标准硅基微米和纳米技术工艺的小型化和生产率以及机械和电气系统行为的限制。 除了同质集成的概念（只有静电致动器），也异构系统（例如结合静电和压电致动）将进行调查，这需要一个通用的和参数化的系统描述和基本的设计规则，这样的系统，特别是考虑到稳定性。作为方法，FEM和Simulink仿真，微米和纳米技术和高分辨率表征技术将被使用。

At very small distances between the electrodes electrostatic actuators provide high energy density and forces. However, at these conditions actuation range is very limited due to pull-in. For sensor applications (gyros: actuation of primary oscillation, accelerometers: force feedback) these limitations are not really important as here only very low actuation ranges (µm) and very low forces (µN) are needed for the almost massless systems. However, as state of the art, electrostatic actuation cannot be used for large range and forces needed for „macro“ applications. State of the art are inch-worm-motors which provide both, large stroke and force, by cooperative function of two clamping actuators with a “moving” actuator. However, these actuator systems are relatively large (smallest multilayer chip ca. 2x2x2 mm³) and cannot be fabricated with monolithical microfabrication.The motivation of this project is to investigate the scientific fundamentals for the realization of electrostatically driven inch-worm like actuator systems based on a large amount of cooperative electrostatic actuators which are miniaturized, can be fabricated by standard Si-technology and which provide both, large stroke (cm) and large forces (N). For that final vision a better understanding of principles, limitations and boundary conditions are needed for microsystem based actuator systems which are built from a huge amount of miniaturized, multistage, multistable and cooperative electrostatic actuators and which provide scalable step size, total range and forces which all can be scaled over several orders of magnitude. A specific scientific question is the influence of non-linear electrostatic force on mechanical stability of each single, distributed multistable and cooperative sub-actuator and of the total actuator system by coupling. Basic questions here are how many of these cooperative and cascaded single actuators can be integrated for a still stable total system and what are the limits for miniaturization, precision and controllability (e.g. caused by roughness and geometrical deviation of fabricated elements within all the actuators). Additionally, a systematic investigation of limitation and cross-coupling for the inherent capacitive sensing provided by each electrostatic actuator (both, in idle and active state) is needed. Further, understanding of miniaturization and producibility using standard Si-based micro- and nanotechnological processes and of the limits of mechanical and electrical system behavior is needed. Besides homogenous integration concepts (only electrostatic actuators), also heterogeneous systems (e.g. combining electrostatic and piezoelectric actuation) will be investigated which needs a general and parametric system description and fundamental design rules for such a system, especially considering stability. As methods, FEM- and Simulink simulation, micro- und nanotechnology and high resolution characterization techniques will be used.