Fabrication of Microfibers with Complex Interior by Shape-Changing Polymers

新一代智能纺织品的信号感知、处理和成像发生在柔性纤维内部，这需要开发具有高度复杂内部结构的纤维制造方法。然而，这是一项极具挑战性的任务。根据我们的经验，我们将开发一种革命性的方法来制造这种纤维，使用可改变形状的聚合物。根据我们的想法，首先将两种聚合物（可变形聚合物和被动聚合物）打印在表面上形成薄膜。这种薄膜的表面可以通过使用任何可用的方法进行图案化，包括允许使用各种材料制造几乎任何多层结构的印刷。然后，由于其中一种聚合物的变形特性，薄膜通过其自滚转变成纤维。通过这种方式，薄膜表面的二维图案在纤维的内部元件中被转换。该项目的中心假设是，聚合物薄膜的纵向折叠行为可以通过改变形状的聚合物链的横向取向来实现，从而形成纤维。反过来，链的横向取向可以通过在非常特定的温度下打印聚合物熔体来实现，这允许拉伸聚合物的沉积，或者通过打印可变形聚合物的预拉伸微纤维来实现。在这个项目中，我们将了解聚合物和取向可控聚合物微纤维沉积的基本原理，以及分子结构和链取向对薄膜折叠的影响。

New generation of smart textiles, where signal perception, processing and imaging occurs inside flexible fibers, requires development of methods for fabrication of fibers with high complex inner architectures. This is, however, extremely challenging task. Basing on own experience, we will develop a revolutionary approach for fabrication of such fibers using shape-changing polymers. According to our idea, two polymers (shape-changing and passive one) are first printed on the surface to form a film. The surface of this film can be patterned by using any available method including printing that allows fabrication of almost any multi-layer structure using various kinds of materials. Then the film is transformed into the fiber by its self-rolling due to shape-changing properties of one of the polymers. In this way, 2D pattern on the film surface is transformed in internal elements of the fibers. The central hypothesis of the project is that the desired longitudinal folding behavior of polymer film leading to formation of a fiber can be achieved by transverse orientation of chains of shape-changing polymer. The transverse orientation of the chains can, in its turn, be achieved either by printing of polymer melt at very specific temperature regime, which allows deposition of stretched polymer, or by printing of pre-stretched microfibers of shape-changing polymer. In this project, we will understand fundamental principles of deposition of polymers and polymer microfibers with controlled orientation as well as effects of molecular architecture and chain orientation on folding of the film.