DMREF: Hydrogel-actuated cellular soft robotic materials with programmable mechanical properties

非技术描述：材料科学和工程的重大挑战之一是设计活性和自适应材料的能力，这些材料可以根据周围环境的特定触发和变化动态改变结构和功能。具有形状变形能力和机械性能按需可编程性的结构材料（即软机器人材料）将在可部署系统、动态光学、软机器人和医学中具有丰富的应用。水凝胶，一类刺激反应材料，是设计这种柔软机器人材料的有希望的成分。水凝胶可以根据不同的环境因素将体积改变几倍。此外，大多数水凝胶是透明的，可拉伸的，并且具有成本效益和环保性。然而，大多数水凝胶又软又脆，它们能产生和承受的应力相当有限。为了提高它们的致动力和机械完整性，它们必须集成在具有更刚性材料和结构的混合系统中。该项目将探索如何将水凝胶单元与精心设计的弹性细胞支架结合起来，以扩大活性成分的输出。激活后，位于支架中的水凝胶肌肉的低应力变形将诱导支架形态的大重构并使其能够工作。技术描述：提议的项目介绍和研究了一类新的主动、可重构和可变形的柔性机器人材料，这些材料具有可编程的机械性能，基于由水凝胶肌肉驱动的弹性细胞结构。目标是建立强大且计算效率高的方法来捕获其高度非线性响应，合成响应外部刺激而产生大变形的水凝胶，识别放大和指导水凝胶响应的细胞结构，开发3D打印策略，实现计算识别材料设计的制造。并解决逆向问题，识别可实现的布局，形成具有期望行为的软机器人物质。在这些研究的指导下，研究团队将探索柔性机器人材料在智能和自适应结构设计中的应用机会，包括机械手、可重构结构和自适应光学。该研究有望通过创建有效的工作流程来实现材料设计能力，从而改变当前软机器人材料的范例，从而确定目标应用程序的最佳细胞微观结构和水凝胶组成。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Description: One of the grand challenges in materials science and engineering is the ability to design active and adaptive materials that dynamically change configuration and functionality in response to specific triggers and changes in the surrounding environment. Architected matter with shape morphing capabilities and on-demand programmability of mechanical properties (i.e., soft robotic materials) will have a wealth of applications in deployable systems, dynamic optics, soft robotics, and medicine. Hydrogels, a class of stimuli-responsive materials, are promising constituents for designing such soft robotic materials. Hydrogels can change their volume by several fold in response to various environmental cues. Furthermore, most hydrogels are transparent and stretchable, as well as cost-efficient and environmentally friendly. However, most hydrogels are soft and brittle and the stresses that they can generate and tolerate are rather limited. To improve their actuation force and mechanical integrity, they have to be integrated in hybrid systems with stiffer materials and structures. The project will explore how to combine hydrogel units with elastomeric cellular scaffolds carefully designed to amplify the output of the active components. Upon activation, low-stress deformations of hydrogel muscles positioned in the scaffolds will induce large reconfigurations in the scaffold morphology and enable work.Technical Description: The proposed project introduces and investigates a new class of active, reconfigurable, and shape-morphing soft robotic materials with programmed mechanical properties based on elastomeric cellular structures actuated by hydrogel muscles. The objective is to establish robust and computationally efficient methods to capture their highly non-linear response, to synthesize hydrogels that generate large deformations in response to external stimuli, to identify cellular architectures that amplify and direct the hydrogels' response, to develop 3D printing strategies that enables fabrication of computationally identified material designs, and to solve the inverse problem of identifying realizable layouts that form soft robotic matter with the desired behavior. Guided by these studies, the research team will then explore opportunities for application of the active soft robotic materials in the design of smart and adaptive structures, including manipulators, reconfigurable structures and adaptive optics. The research is expected to enable material design capabilities that shift the current paradigm for soft robotic materials by creating an efficient work-flow that given a target application identifies the optimal cellular microstructure and hydrogel composition.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.