Micromechanics of Materials, Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
Department of Chemical Engineering and Chemistry & Institute for Complex Molecular Systems (ICMS), Technology University of Eindhoven, 5600 MB Eindhoven, The Netherlands.
Soft Matter. 2019 Oct 28;15(40):8040-8050. doi: 10.1039/c9sm01594a. Epub 2019 Oct 9.
Nature employs travelling waves to generate propulsion of fluids, cells and organisms. This has inspired the development of responsive material systems based on different external triggers. Especially light-actuation is suitable because of its remote control and scalability, but often complex, moving light sources are required. Here, we developed a method that only requires flood exposure by rotating the linear polarization of light to generate propagating surface waves on azobenzene-modified liquid crystalline polymer films. We built a photomechanical computational model that accounts for the attenuation of polarized light and trans-to-cis isomerization of azobenzene. A non-uniform in-plane distribution of the liquid crystal molecules allows for the generation of travelling surface waves whose amplitude, speed and direction can be controlled through the intensity, rotation direction and rotation speed of the linear polarization of a light source. Our method opens new avenues for motion control based on light-responsive topographical transformations for application in microfluidic lab-on-chip systems and soft robotics.
大自然利用行波来产生流体、细胞和生物的推动力。这启发了人们开发基于不同外部触发因素的响应材料系统。特别是光致动非常适合，因为它可以远程控制和扩展，但通常需要复杂的、移动的光源。在这里，我们开发了一种仅需旋转线性偏振光即可在偶氮苯修饰的液晶聚合物薄膜上产生传播表面波的方法。我们建立了一个光机械计算模型，该模型考虑了偏振光的衰减和偶氮苯的顺反异构化。液晶分子的非均匀面内分布允许产生行波，其幅度、速度和方向可以通过光源的线性偏振强度、旋转方向和旋转速度来控制。我们的方法为基于光响应形貌变换的运动控制开辟了新的途径，可应用于微流控芯片系统和软机器人领域。
