GOALI/Collaborative Research: Autonomous Thermomechanical Fabrication of 3D Structures using Heat-Responsive Polymers

GOALI/合作研究：使用热响应聚合物自主热机械制造 3D 结构

• 批准号: 1635966
• 负责人: M Ravi Shankar
• 金额: $ 17.5万
• 依托单位: University of Pittsburgh
• 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: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1635966&HistoricalAwards=false
• 关键词: GOALI; Collaborative; Research; Autonomous; Thermomechanical

Autonomously fabricating macro-scale polymeric objects by subjecting a preform to a non-contact stimulus such as heat holds significant technological implications. For instance, it offers the ability to transform a preform (fabricated in simple, compact geometries) into target shapes on demand. It also offers the ability to simultaneously transform a large number of parts into target shapes by triggering them en masse using a globally applied stimulus. Hence, mass manufacturability emerges without an additional overhead. This Grant Opportunity for Academic Liaison with Industry (GOALI) award supports fundamental research on the self-assembly of 3D structures based on designs embedded at the molecular level in heat-responsive polymers. Research results can help spawn new technologies in applications such as biomedicine, where implants can be deployed into desired shapes and reshaped as-needed using an external stimulus.The first research objective is to establish the relationship between the spatiotemporal evolution of strain fields (leading to the creation of 3D helical structures) and controllable parameters (nematic director orientation and temperature). To achieve this objective, crosslinked, acrylate-based liquid crystalline polymers in twisted nematic configurations will be synthesized. Freely suspended polymer samples will be subjected to heat treatment with varying nematic director orientation (ranging from 0 to 45° with respect to the mid-plane of samples) and temperature (ranging from the glass transition temperature to close to the thermal decomposition temperature). The evolution of strain fields in these samples will be measured in situ using image analysis based characterization. The second research objective is to establish the effect of the displacement (preimposed on the sample) on the spatiotemporal evolution of torsional, bending strain fields (underpinning the creation of 3D prismatic and hierarchically supercoiled shapes). Various displacements (up to 20 percent of the length of the samples) will be imposed to samples. Spatiotemporal evolution of torsional, bending strain fields will be measured using imaging analysis based characterization.

通过将预制件置于非接触刺激(如热)下自主制造宏观规模的聚合物对象具有重大的技术意义。例如，它提供了根据需要将预制件(以简单、紧凑的几何形状制造)转换为目标形状的能力。它还提供了通过使用全球应用的刺激集体触发大量部件来同时将大量部件转换为目标形状的能力。因此，在没有额外费用的情况下，出现了大规模制造能力。这一学术联系机会奖(GOALI)支持基于嵌入在热响应性聚合物中的分子水平的设计的3D结构自组装的基础研究。研究结果有助于在生物医学等应用中催生新技术，在生物医学中，植入物可以部署成所需的形状，并可以使用外部刺激根据需要重塑形状。第一个研究目标是建立应变场的时空演变(导致创建3D螺旋结构)与可控参数(向列相指向矢方向和温度)之间的关系。为了实现这一目标，将合成具有扭曲向列构型的交联型丙烯酸酯基液晶聚合物。自由悬浮聚合物样品将进行不同向列相取向(相对于样品中面0°到45°)和温度(从玻璃化转变温度到接近热分解温度)的热处理。这些样品中应变场的演变将使用基于图像分析的表征进行现场测量。第二个研究目标是确定位移(预先施加在样品上)对扭转、弯曲应变场的时空演变的影响(支持创建3D棱柱形和层次化超螺旋形状)。将对样品施加各种位移(最高可达样品长度的20%)。将使用基于成像分析的表征来测量扭转、弯曲应变场的时空演变。

项目成果

Complexity from simplicity: Confinement directs morphogenesis and motility in nematic polymers

• DOI: 10.1016/j.eml.2021.101362
• 发表时间: 2021-08
• 期刊: Extreme Mechanics Letters
• 影响因子: 4.7
• 作者: A. Clement;M. Babaei;J. Phadikar;Da‐Wei Lee;A. Skandani;M. Shankar

Visco-plastic self-consistent modeling of crystallographic texture evolution related to slip systems activated during machining Ti-6AL-4V

与加工 Ti-6AL-4V 期间激活的滑移系统相关的晶体织构演化的粘塑性自洽建模

• DOI: 10.1016/j.jallcom.2020.157336
• 发表时间: 2021
• 期刊: Journal of Alloys and Compounds
• 影响因子: 6.2
• 作者: Wang, Qingqing;Shankar, Ravi M.;Liu, Zhanqiang
• 通讯作者: Liu, Zhanqiang

Effect of microstructural anisotropy on severe plastic deformation during material removal at micrometer length-scales

微米长度尺度材料去除过程中微观结构各向异性对严重塑性变形的影响

• DOI: 10.1016/j.matdes.2020.108874
• 发表时间: 2020
• 期刊: Materials & Design
• 影响因子: 8.4
• 作者: Gong, Shan;Shankar, M. Ravi
• 通讯作者: Shankar, M. Ravi

Mapping dislocation densities resulting from severe plastic deformation using large strain machining

• DOI: 10.1557/jmr.2018.264
• 发表时间: 2018-08
• 期刊: Journal of Materials Research
• 影响因子: 2.7
• 作者: Sepideh Abolghasem;S. Basu;S. Shekhar;M. Ravi Shankar

Tuned photomechanical switching of laterally constrained arches

横向约束拱门的调谐光机械切换

• DOI: 10.1088/1361-665x/ab1ce4
• 发表时间: 2019
• 期刊: Smart Materials and Structures
• 影响因子: 4.1
• 作者: Smith, M L;Gao, J;Skandani, A A;Deering, N;Wang, D H;Sicard, A A;Plaver, M;Tan, L-S;White, T J;Shankar, M R
• 通讯作者: Shankar, M R