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Preparation of Janus-type actuators based on liquid crystalline elastomers in a mircrofluidic device

微流控装置中基于液晶弹性体的Janus型执行器的制备

基本信息

批准号：
251402731
负责人：
Professor Dr. Rudolf Zentel
金额：
--
依托单位：
Department Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/251402731?language=en
关键词：
Preparation Janus type actuators based

项目摘要

This project is based on recent work, which was partly supported by DFG (Ze 230/19). During it we succeeded in making micrometer sized particles from liquid crystalline elastomers (LCEs) in a microfluidic device, which change their shape reversibly during temperature variation (heating above a phase transition). It is possible to prepare the actuating particles in the shape of spheres, rotational ellipsoids or fibers by variation of the parameters in the microfluidic device and to apply the preparation process to different liquid crystalline materials. The type of actuation depends thereby on the director field inside the particle. Thus particles, which either expand or contract, can be made from the same LCE-material by varying the process parameters and thereby the director field. Very recently also core-shell systems became available, which reversibly pump the liquid core into (or out off) a capillary during the actuation process.Starting from this experience we intend to increase the complexity of the actuating particles from LCEs. For this purpose we want to reduce the symmetry by producing actuating janus-type particles in a microfluidic device. The actuating particles, made so far, deform in a symmetric way (to both sides). The fixation of a second, non actuating particle (i.e. the preparation of a janus-type structure) will break the symmetry and lead to a directed actuation. In this way a directed motion in one direction (the preparation of a swimmer) might get possible. In a second step it will be the goal to combine two parts in the janus-like structure, which actuate independent of each other as a result of two different stimuli (temperature or light). To achieve this goal 3 tasks have to be resolved: At first it will be necessary to construct a suitable microfluidic device. Then (2) it will be necessary to establish two suitable not-miscible liquid crystalline polymer systems, because both parts of the janus structure are, at first, liquid like (prior to cross linking) and a mixing must be prohibited. Finally (3) it is necessary to develop a photo-addressable LCE-component, which can be handled under the boundary conditions of the microfluidic process.

该项目以最近的工作为基础，该工作得到了德国政府的部分支持(ZE 230/19)。在此过程中，我们成功地在微流控装置中从液晶弹性体(LCE)中制备出微米级的颗粒，这些颗粒在温度变化(在相变以上加热)时可逆地改变形状。通过改变微流控装置中的参数，可以制备球形、旋转椭球或纤维形状的致动粒子，并将该制备方法应用于不同的液晶材料。因此，激励的类型取决于粒子内部的指向矢场。因此，通过改变工艺参数，从而改变指向矢场，可以从相同的LCE材料制备膨胀或收缩的粒子。最近还出现了核壳系统，它在驱动过程中将液体核可逆地泵入(或泵出)毛细管。从这个经验开始，我们打算增加来自LCE的驱动粒子的复杂性。为此，我们希望通过在微流控装置中产生致动的Janus型粒子来降低对称性。到目前为止，激励粒子以对称的方式变形(向两侧)。第二个非致动粒子的固定(即制备Janus型结构)将破坏对称性并导致定向致动。这样，一个方向的定向运动(游泳者的准备)就有可能实现。在第二步中，我们的目标是将两个部分结合在类似Janus的结构中，由于两个不同的刺激(温度或光)，这两个部分相互独立地驱动。为了实现这一目标，必须解决三项任务：首先，必须构建一个合适的微流控装置。然后(2)有必要建立两个合适的不相容的液晶聚合物体系，因为Janus结构的两个部分首先是类似液体的(在交联之前)，并且必须禁止混合。最后(3)有必要开发一种可以在微流控过程的边界条件下处理的光寻址液晶组件。