Mechanics of Bioinspired Soft Slender Actuators for Programmable Multimodal Deformation

柔性细长致动器是一种主动结构，它的一个维度比其他维度大得多，并且在自然界中无处不在。一般来说，这些结构具有无限多的自由度，这使得它们难以高精度地进行操作。迫切需要有效的理论和计算工具来指导高精度驱动器的设计。受象鼻运动的启发，本项目从根本上研究了可编程多通道驱动下的柔性细长执行器的力学问题。降维使得所提出的模型在计算上高效、廉价和健壮，特别是考虑到大变形和逆分析。拟议的活动可以提供机会，将软机器人研究从试错方法转变为以科学为基础的设计战略。这项工作可以作为促进STEM教育的平台。经过验证后，该模型将在一个开源模拟器中实现，该模拟器可供学生、教育工作者和软机器人社区的研究人员使用。该模型将为软机器人在各种高精度应用中提供新的设计策略，包括可穿戴设备、柔性电子设备和外科机器人。该项目集成了理论建模、计算力学、材料多物理、实验力学和机器学习来解决研究问题。将力学模型和实验验证相结合，建立一个开源的仿真平台，以优化此类执行器的设计。其基本结构是主动细丝理论，它利用降维的概念--从完全三维结构到主动基尔霍夫杆--仅通过拉伸、曲率和扭转来描述变形。它将创建一个开放源代码的模拟器，并将与更广泛的软机器人社区共享。这项研究将首次建立一种新的力学理论来预测柔性细长执行器末端执行器的轨迹。然后可以作为优化末端执行器轨迹的基础。这一新理论将通过液晶弹性纤维的驱动实验得到验证。该项目将涉及理论和实验的同步发展，并将反复修改这两项活动，以最终建立经过实验验证的理论和具有高预测精度的优化设计模型。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Soft slender actuators are active structures that have one dimension much larger than the other dimensions, and are ubiquitous in nature. In general, these structures have an infinite number of degrees of freedom, making them challenging to manipulate with high precision. There is an urgent need for efficient theoretical and computational tools to guide actuator design for high precision actuation. Inspired by elephant-trunk motion, this project fundamentallly investigates the mechanics of soft slender actuators under programmable multimodal actuation. Dimensional reduction makes the proposed model computationally efficient, inexpensive, and robust, especially with a view towards large deformations and inverse analyses. Proposed activties can provide opportunities to transform soft robotic research from a trial-and-error approach to a science-based design strategy. The work can serve as a platform to promote STEM education. After validation, the model will be implemented in an open-source simulator that can be used by students, educators, and researchers in the soft robotics community. The model will inform new design strategies for soft robots in various high-precision applications including wearable devices, flexible electronics, and surgical robotics.This project integrates theoretical modeling, computational mechanics, material multiphysics, experimental mechanics, and machine learning to address the research problem. Mechanics models and experimental validation will be combined to establish an open-source simulation platform to optimize the design of such actuators. The underlying construct is the active filament theory that harnesses the concept of dimensional reduction—from a fully three-dimensional structure to an active Kirchhoff rod—by describing deformation exclusively through extension, curvature, and torsion. It will create an open-source simulator that will be shared with the broader, soft robotics, community . The research will first establish a new mechanics theory to predict the trajectory of the end effector of a soft slender actuator. It can then serve as the foundation to optimize the trajectory of the end effector. The new theory will be validated via experiments through the actuation of liquid crystal elastomer fibers. This project will involve the simultaneous development of theory and experiments and will iteratively revise both activities to ultimately establish an experimentally validated theory and an optimal design model with high predicting accuracy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.