EAGER: Stereolithography-based Multi-material Additive Manufacturing of Particle-reinforced Composite Lattices to Achieve Tunable Negative-Thermal-Expansions

EAGER：基于立体光刻的颗粒增强复合晶格多材料增材制造，以实现可调节的负热膨胀

• 批准号: 1649093
• 负责人: Qiming Wang
• 金额: $ 10万
• 依托单位: University of Southern California
• 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: 2016-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1649093&HistoricalAwards=false
• 关键词: EAGER; Stereolithography; based; Multi; material

Solid materials usually expand when heated. This property may induce severe thermal mismatch problems in a wide range of engineering settings. It is highly desirable to manufacture materials with nearly-zero or negative thermal expansions that can mitigate the thermal mismatch. One promising approach is to harness the geometrical interactions within composite lattice structures composed of constituents of distinctive thermal expansion coefficients. However, it is difficult to fabricate 3D composite lattices with multiple distinctive components and highly sophisticated geometries. This EArly-concept Grant for Exploratory Research (EAGER) award supports fundamental research on a stereolithography-based multi-material additive manufacturing process that can make 3D particle-reinforced composite lattices with tunable negative thermal-expansions. Research results will benefit a number of applications where thermal stress should be carefully managed, including bridge joints, microchip devices, adhesive fillers, dental fillings, and high precision optical or mechanical devices that experience variable temperatures.In the stereolithography-based multi-material additive manufacturing process, two types of photoresins (with and without particle reinforcement) are procured layer by layer to form two types of photoresin beams alternately. When experiencing rising temperature, the two types of beams with different thermal expansion coefficients interact with each other to induce an overall negative-thermal-expansion of the composite lattice. The first research objective is to establish the relationships between the photocuring depth of the particle-reinforced photoresins and manufacturing parameters (light intensity, photoexposure time, particle type, and particle volume fraction). To achieve this objective, a frontal photopolymerization model will be developed to elucidate the transition from liquid to solid of reinforced-photoresins under ultraviolet radiation. It will be used to predict photocuring depth as a function of manufacturing parameters. Some model predictions will be compared against with photocuring experiments with varied light intensity (5-100 W/m^2), photoexposure time (0.5-300 s), particle type (copper, silica, iron, and alumina), and particle volume fraction (0-10 percent). The second research objective is to understand the effects of lattice geometric parameters (reinforced beam length, angle between reinforced and unreinforced beams) and particle volume fraction on the negative-thermal-expansion of the composite lattices. To achieve this objective, an analytical thermoelastic model will be constructed to describe the thermal-induced geometrical interactions between photoresin beams within the composite lattices. Based on the model, the negative thermal expansion of the composite lattices will be analytically predicted for different values of lattice geometric parameters and particle volume fraction. Thermal expansion experiments on manufactured composite lattices will be conducted in a thermal chamber with temperature control. Reinforced beam length will be varied from 2 to 2.8 mm, beam angle from 60 to 90 degrees, and particle volume fraction from 2 percent to 10 percent. The negative-thermal-expansion of the composite lattices will be measured from image sequences taken by a digital camera during the temperature variation.

固体材料通常在加热时扩展。该特性可能会在各种工程环境中引起严重的热不匹配问题。非常需要制造具有近零或负热膨胀的材料，以减轻热不匹配。一种有希望的方法是利用由独特的热膨胀系数组成的复合晶格结构内的几何相互作用。但是，很难制造具有多个独特成分和高度复杂的几何形状的3D复合晶格。 这项探索性研究（急切）奖的早期概念授予授予基于立体光刻的多物质添加剂制造过程的基础研究，该过程可以使3D粒子增强的复合晶格具有可调的负热表达。研究结果将受益于应仔细管理热应力的许多应用，包括桥接接头，微芯片设备，粘合剂填充剂，牙齿填充物，牙齿填充物以及高精度的光学或机械设备，具有可变温度。在基于刻板学的多物质添加剂制造过程，具有隔离式的二层层面层的固定性添加剂过程，具有两种类型的层层。当体验到温度上升时，具有不同热膨胀系数的两种类型的梁相互相互作用，以诱导复合晶格的总体负膨胀。第一个研究目标是建立粒子增强光蛋白的光关节深度与制造参数（光强度，光曝光时间，粒子类型和粒子体积分数）之间的关系。为了实现这一目标，将开发一个额叶光聚合模型，以阐明在紫外线辐射下从液体到固体的过渡。它将用于预测光化深度作为制造参数的函数。与光强度不同（5-100 W/m^2），光曝光时间（0.5-300 s），粒子类型（铜，硅，铁和氧化铝）以及粒子体积分数（0-10％）的光强度（5-100 W/m^2），光曝光时间（0.5-300 s）和粒子类型（0-10％）的光相位实验（0-10％）。第二个研究目标是了解晶格几何参数（增强梁长度，增强和未增强的束之间的角度）和颗粒体积分数对复合晶格的负热扩张的影响。为了实现这一目标，将构建一个分析热弹性模型，以描述复合晶格内光雷素束之间的热诱导的几何相互作用。基于模型，将分析复合晶格的负热膨胀，以预测晶格几何参数和粒子体积分数的不同值。制成的复合晶格的热膨胀实验将在温度控制的热室中进行。增强梁的长度将从2到2.8毫米，光束角度从60到90度，粒子体积分数从2％到10％。复合晶格的负电量扩展将是根据数码相机在温度变化期间拍摄的图像序列来测量的。

项目成果

Role of Extracellular Matrix in the Biomechanical Behavior of Pancreatic Tissue

• DOI: 10.1021/acsbiomaterials.8b00349
• 发表时间: 2018-05-01
• 期刊: ACS BIOMATERIALS SCIENCE & ENGINEERING
• 影响因子: 5.8
• 作者: Hudnut, Alexa W.;Lash-Rosenberg, Lian;Armani, Andrea M.
• 通讯作者: Armani, Andrea M.

Magnetoactive Acoustic Metamaterials

• DOI: 10.1002/adma.201706348
• 发表时间: 2018-05
• 期刊: Advanced Materials
• 影响因子: 29.4
• 作者: Kunhao Yu;N. Fang;Guoliang Huang;Qiming Wang

Lightweight Mechanical Metamaterials with Tunable Negative Thermal Expansion

• DOI: 10.1103/physrevlett.117.175901
• 发表时间: 2016-10-21
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Wang, Qiming;Jackson, Julie A.;Fang, Nicholas X.
• 通讯作者: Fang, Nicholas X.