Dynamics and control of micropolar material structures with embedded angular momentum

30年前，有人提出将包含大量陀螺仪的结构系统建模为具有嵌入的连续角动量分布的弹性连续体。这一想法来自空间科学界，在那里，非常大的空间平台（卫星）的概念很受欢迎，控制其形状和方向的方法也很有趣。最初的工作建立了结构形状控制的想法的优点，但兴趣减弱，因为这些系统将不会实现，由于其成本。 应用这一思想的一个新的机会在于规模范围的另一端。微机电（MEMS）器件为构建“智能”材料系统提供了前所未有的机会，这些材料系统将在宏观上显示传统材料不可能的行为。随着微米和纳米器件制造的不断发展，如果有令人信服的理由，可以创建包含嵌入式，独立和可控的角动量分布的材料。具有这些属性的材料，以前被称为回转材料，很少受到关注，但以前的工作已经建立了它们的结构形状控制的潜力。这种能力可以有利地结合在光学装置中以调谐反射镜，在航空应用中的边界层行为的主动控制中，或者可能在非常小的形状变化可能是有利的外科手术器械中。有许多潜在的应用。这些材料模型需要一个不对称的应力张量，它已被证明，材料模型，假设不对称的应变和应力张量是有效的，适用于在微米尺度。因此，建议调查的材料和结构系统的动力学与分布的惯性，弹性，耗散和陀螺仪的影响的基本贡献进行使用微极弹性理论。

Thirty years ago it was proposed to model structural systems that contained a very large number of gyroscopes as an elastic continuum with an embedded continuous distribution of angular momentum. The idea came from the astronautics community where the notion of very large space platforms (satellites) was popular and means of controlling their shape and orientation were of interest. Initial work established the merits of the idea for structural shape control but interest waned because these systems would not be realized owing to their cost. A new opportunity for application of this idea lies at the opposite end of the scale spectrum. Micro-Electro-Mechanical (MEMS) devices offer an unprecedented opportunity to build "smart" material systems that will macroscopically display behaviours not possible with conventional materials. With the ongoing developments in micro and nano device fabrication a material that contains an embedded, independent and controllable distribution of angular momentum could be created, should there be compelling reasons to do so. Materials with these attributes, previously referred to as gyric materials, have received scant attention but prior work has established their potential for structural shape control. This ability could be beneficially incorporated in optical devices to tune mirrors, in the active control of boundary layer behaviour in aeronautic applications, or possibly in surgical instruments where very small shape changes may be advantageous. There are many potential applications. These material models require an asymmetric stress tensor and it has been shown that material models that assume asymmetric strain and stress tensors are effective and applicable at the micron scale. Hence it is proposed that an investigation into the dynamics of material and structural systems with fundamental contributions from distributed inertial, elastic, dissipative, and gyroscopic influences be undertaken using a micropolar theory of elasticity.