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

通过使预成型件经受非接触刺激（例如热）来自主制造宏观尺度聚合物物体具有显著的技术含义。例如，它能够根据需要将预制件（以简单紧凑的几何形状制造）转换为目标形状。它还提供了通过使用全局施加的刺激来触发大量零件同时将其转换为目标形状的能力。因此，在没有额外开销的情况下出现了大规模制造能力。 这个学术联络与工业（GOALI）奖的赠款机会支持基于嵌入在热响应聚合物分子水平上的设计的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，其中植入物可以部署成所需的形状，并根据需要使用外部刺激进行重塑。第一个研究目标是建立应变场的时空演变（导致3D螺旋结构的创建）和可控参数（指向矢方向和温度）之间的关系。为了实现这一目标，将合成具有扭曲双构型的交联的丙烯酸酯基液晶聚合物。自由悬浮的聚合物样品将经受具有变化的指向矢取向（相对于样品的中平面为0至45°）和温度（从玻璃化转变温度至接近热分解温度的范围）的热处理。将使用基于图像分析的表征原位测量这些样品中应变场的演变。第二个研究目标是建立扭转，弯曲应变场的时空演变的位移（预先施加在样品上）的效果（支持创建3D棱柱和分层超螺旋形状）。将对样品施加各种位移（最多为样品长度的20%）。扭转，弯曲应变场的时空演变将使用基于成像分析的表征进行测量。

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 spawning 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.