Zhang Mengjie, Fan Xiru, Dong Le, Jiang Chengru, Weeger Oliver, Zhou Kun, Wang Dong
State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Meta Robotics Institute, Shanghai Jiao Tong University, Shanghai, 200240, China.
Adv Sci (Weinh). 2024 Jul;11(28):e2309932. doi: 10.1002/advs.202309932. Epub 2024 May 20.
Grayscale digital light processing (DLP) printing is a simple yet effective way to realize the variation of material properties by tuning the grayscale value. However, there is a lack of available design methods for grayscale DLP 3D-printed structures due to the complexities arising from the voxel-level grayscale distribution, nonlinear material properties, and intricate structures. Inspired by the dexterous motions of natural organisms, a design and fabrication framework for grayscale DLP-printed soft robots is developed by combining a grayscale-dependent hyperelastic constitutive model and a voxel-based finite-element model. The constitutive model establishes the relationship between the projected grayscale value and the nonlinear mechanical properties, while the voxel-based finite-element model enables fast and efficient calculation of the mechanical performances with arbitrarily distributed material properties. A multiphysics modeling and experimental method is developed to validate the homogenization assumption of the degree of conversion (DoC) variation in a single voxel. The design framework is used to design structures with reduced stress concentration and programmable multimodal motions. This work paves the way for integrated design and fabrication of functional structures using grayscale DLP 3D printing.
灰度数字光处理（DLP）打印是一种通过调整灰度值来实现材料性能变化的简单而有效的方法。然而，由于体素级灰度分布、非线性材料特性和复杂结构所带来的复杂性，目前缺乏适用于灰度DLP 3D打印结构的可用设计方法。受自然生物体灵巧运动的启发，通过结合灰度相关的超弹性本构模型和基于体素的有限元模型，开发了一种用于灰度DLP打印软机器人的设计与制造框架。本构模型建立了投影灰度值与非线性力学性能之间的关系，而基于体素的有限元模型能够快速有效地计算具有任意分布材料特性的力学性能。开发了一种多物理场建模与实验方法，以验证单个体素中转化率（DoC）变化的均匀化假设。该设计框架用于设计具有降低应力集中和可编程多模态运动的结构。这项工作为使用灰度DLP 3D打印进行功能结构的集成设计和制造铺平了道路。
