Collaborative Research: Using Boundaries to Create and Control Pathways for Photomechanical Actuation

合作研究：利用边界创建和控制光机械驱动路径

• 批准号: 1635407
• 负责人: Kaushik Dayal
• 金额: $ 25万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1635407&HistoricalAwards=false
• 关键词: Collaborative; Research; Using; Boundaries; Create

This award supports fundamental research into new ways to hold and constrain liquid crystal elastomers that will cause thin sheets to change shape in discrete steps as the sheets are illuminated. Liquid crystal elastomers are a class of polymers that can be tailored to undergo changes in shape when they are illuminated with light, thereby enabling the direct conversion of light into directed mechanical work. An important advantage of using light is that wiring, circuitry, and mechanical contacts are not needed; devices made of these materials can be operated remotely. This property can enable applications in a range of technologies, including light-operated microsurgical tools, display technologies integrated with touch feedback, and robotics that harness light for manipulation. However, the mechanical force generated by these materials is small and the shape change during irradiation with light is difficult to control. The new shape change mechanisms will simultaneously generate fast response times and large forces during the transition between the shapes. Therefore, the results of this research can enable new device architectures and bring these materials closer to widespread application, thereby benefitting the US economy and society. Outreach to underrepresented K-12 students through local Pittsburgh organizations will also be integrated with the research program. Light-driven shape change observed in liquid crystal elastomers can enable a class of next-generation of remotely-driven actuators. This research will explore the interplay between the photomechanical adaptivity and localized constraints applied at the boundary. In particular, this interplay triggers a cascade of discrete transitions from a prior flat state into non-self-similar shapes. Integrated experiments and modeling will be used to understand the interactions between microstructural heterogeneity, boundary conditions, material anisotropy and photostrains on the emergent multimorphism and actuation. The resulting core contribution to mechanics will be the deeper fundamental understanding of the interplay between instabilities and boundary conditions in two-dimensional objects with complex curvature and heterogeneity, using shell and membrane theories from mechanics. The research tasks include synthesis of thin-film specimens, characterization of light-induced mechanical deformation, development of mathematical models, and numerical and analytical analysis of the models. The feedback between experiment and theory will enable the formulation of predictive and accurate models, as well as provide physics-based guidance to the experiments.

该奖项支持基础研究，以新的方式来保持和约束液晶弹性体，这将导致薄片在离散步骤中改变形状，因为片材被照亮。 液晶弹性体是一类聚合物，当它们被光照射时，它们可以被定制为经历形状的变化，从而能够将光直接转换为定向机械功。使用光的一个重要优点是不需要布线，电路和机械接触;由这些材料制成的设备可以远程操作。 这种特性可以在一系列技术中实现应用，包括光控显微手术工具、集成触摸反馈的显示技术以及利用光进行操纵的机器人技术。 然而，这些材料产生的机械力很小，并且在光照射期间的形状变化难以控制。新的形状变化机制将在形状之间的过渡期间同时产生快速响应时间和大的力。 因此，这项研究的结果可以实现新的器件架构，并使这些材料更接近广泛应用，从而使美国经济和社会受益。通过匹兹堡当地组织对代表性不足的K-12学生的外联也将与研究计划相结合。在液晶弹性体中观察到的光驱动形状变化可以实现一类下一代远程驱动致动器。 本研究将探讨在边界处应用的照相机械适应性和局部约束之间的相互作用。 特别是，这种相互作用触发了从先前平坦状态到非自相似形状的离散过渡的级联。综合实验和建模将被用来了解微观结构的异质性，边界条件，材料各向异性和光应变的涌现多晶型和驱动之间的相互作用。 由此产生的核心贡献力学将是更深入的基本理解之间的相互作用的不稳定性和边界条件在二维物体复杂的曲率和异质性，使用壳和膜理论力学。 研究任务包括薄膜样品的合成，光致机械变形的表征，数学模型的开发，以及模型的数值和分析分析。 实验和理论之间的反馈将能够制定预测和准确的模型，并为实验提供基于物理的指导。

项目成果

Disclinations without gradients: A nonlocal model for topological defects in liquid crystals

无梯度向错：液晶拓扑缺陷的非局域模型

• DOI: 10.1016/j.eml.2018.07.005
• 发表时间: 2018
• 期刊: Extreme Mechanics Letters
• 影响因子: 4.7
• 作者: de Macedo, Robert Buarque;Pourmatin, Hossein;Breitzman, Timothy;Dayal, Kaushik
• 通讯作者: Dayal, Kaushik

Steering with light: indexable photomotility in liquid crystalline polymers

• DOI: 10.1039/c7ra10619j
• 发表时间: 2017-11
• 期刊: RSC Advances
• 影响因子: 3.9
• 作者: M. Babaei;J. Clément;K. Dayal;M. Shankar

Phase-Field Finite Deformation Fracture with an Effective Energy for Regularized Crack Face Contact

• DOI: 10.1016/j.jmps.2022.104994
• 发表时间: 2022-06
• 作者: Maryam Hakimzadeh;Vaibhav Agrawal;K. Dayal;C. Mora-Corral

Surface Growth in Deformable Solids using an Eulerian Formulation

使用欧拉公式在可变形固体中进行表面生长

• DOI: 10.1016/j.jmps.2021.104499
• 发表时间: 2021
• 期刊: Journal of the mechanics and physics of solids
• 影响因子: 5.3
• 作者: Naghibzadeh, Kiana;Walkington, Noel;Dayal, Kaushik
• 通讯作者: Dayal, Kaushik

Symmetry-Adapted Tight-Binding Electronic Structure Analysis of Carbon Nanotubes with Defects, Kinks, Twist, and Stretch

具有缺陷、扭结、扭曲和拉伸的碳纳米管的对称性紧结合电子结构分析

• DOI: 10.1177/1081286520961831
• 发表时间: 2020
• 期刊: Mathematics and mechanics of solids
• 影响因子: 2.6
• 作者: Mukherjee, Soumya;Pourmatin, Hossein;Wang, Yang;Breitzman, Timothy;Dayal, Kaushik
• 通讯作者: Dayal, Kaushik