Printed polymer shape memory structures

具有形状记忆行为的结构是自适应电子研究的主题。某些聚合物能够在一定条件下改变其形状。它们易于生产，编程和具有低密度。今天的3D打印机可以直接打印结构，这些结构能够在打印后直接在能量输入下变形或组装。初步实验表明，用市售FDM打印机从市售FDM长丝的4个聚合物层打印的简单结构能够在热的影响下改变其几何形状。在通过加热活化之后，结构可以在仍然热的时候成形为任何形状，然后冷却并保持新的形状。随后的加热释放了材料中的内应力，结构恢复到其预定形状。对打印机的成本有效的修改，例如类似于切割机的第二材料处理单元，使得可以将联合收割机FDM丝与含金属的导电油墨和导电丝组合，这又使得可以通过电阻加热来实现热输入。从初始实验中获得的数据表明，形状可变性的性能在很大程度上取决于所使用的印刷参数和环境条件。项目应通过系统调查提供证据。在本项目中，应详细研究印刷工艺及其对形状可变性的影响。将使用视觉显微镜和热成像相机来详细研究印刷过程和印刷过程中的温度分布。用于测试4D打印结构的特殊测试台将与测量方法一起开发。测量了锁紧力、疲劳、驱动速度等性能参数，并改变了生产参数。对压力参数和温度梯度分布的系统研究应能更好地理解打印结构的形状可变性的功能。实验研究与数学模型相结合，应该会导致一个非常好理解的4D打印过程。

Structures with shape memory behavior are the subject of adaptronic research. Certain polymers are able to change their shape under certain conditions. They are easy to produce, program and have a low density. Today's 3D printers make it possible to directly print structures that are able to deform or assemble themselves under energy input directly after printing. Initial experiments show that simple structures printed with commercially available FDM printers from 4 polymer layers of commercially available FDM filaments are capable of changing their geometry under the influence of heat. After activation by heat, the structures can be shaped into any shape while still hot, then cooled and retained in the new shape. Subsequent heating releases the internal stresses in the material and the structure returns to its predefined shape. Cost-effective modifications to the printer, such as a syringe-like second material processing unit, make it possible to combine FDM filaments with metal-containing conductive inks and conductive filaments, which in turn make it possible to achieve the heat input by resistive heating. The data obtained from initial experiments show that the performance of shape variability depends very much on the printing parameters used and the environmental conditions. The project shall provide the proof by systematic investigations. In this project the printing process and its influence on the shape variability shall be investigated in detail. A visual microscope together with a thermal imaging camera will be used to investigate the printing process and the temperature distribution during printing in detail. Special test benches for testing 4D printing structures will be developed together with measurement methods. Performance parameters such as blocking force, fatigue, actuating speed are measured and production parameters are changed. The systematic investigation of the pressure parameters and the distribution of the temperature gradients should lead to a better understanding of the function of the form variability of the printed structures. The experimental investigations together with mathematical models should lead to a very well understood 4D printing process.