The blue line represents the simulated curve, whereas the red line represents the experimental curve. 1b, the oscillation of the transmittance was measured by rotating the LC cell (TBA 107, Autronic). Therefore, an untreated PDMS film, referred to here as ‘intrinsic PDMS,’ can allow for various LC orientations. The formation of the schlieren texture is attributed to the non-anisotropic nature of the method, which is in contrast to the rubbing method or ion-beam treatment 1, 3, 4. 1a, there are 3 singularity points, each of which is associated with two black ‘brushes’, which extend in different directions for each singularity. Specific optical patterns, which are known as the schlieren texture of the nematic phase, were observed. The alignment state of an LC cell fabricated using polydimethylsiloxane (PDMS) films was investigated via polarising optical microscopy (POM) images, as shown in Fig. When the necessary wrinkle conditions were satisfied, we observed that LC molecules could be stably and homogeneously aligned on the locally treated surface. We also observed a smooth surface on the near side of the wrinkle structure, which was an untreated region. However, the proper localised exposure of the surface to IB radiation produces a wrinkle structure and results in a height difference between the wrinkles and the non-treated regions. Under certain source conditions, wrinkled walls cannot form. By changing the width of the mask pattern and the intensity of the surface-treatment source, we can control the stability of the LC alignment. Herein, we propose a method for the self-alignment of positive LC molecules via a localised surface treatment using ion-beam (IB) irradiation that passes through a long localised pattern. There is a need for additional studies regarding this effect in the context of various applications. Moreover, there may be either an indirect or direct effect on the non-treated regions between the treated regions, which has been the subject of little study. When a soft material is partially treated using focused ion beams (FIBs), a wrinkle structure forms, thereby yielding a height difference between the non-treated and exposed surfaces. Additionally, chemical patterns are used to anchor liquid crystals (LCs), which has the limitation of being a complicated process that uses various chemical products 8. However, this method has the limitation that LC molecules are confined in a microstructure 7. One of the methods uses a wrinkle structure for the fabrication of arrays of open micro-channel capillaries. Several experimental methods for anchoring LCs on patterned substrates are known. Localised patterning is a common interest in surface science. Recently, to achieve stable alignment using a non-contact method, LC molecules have been self-aligned on an alignment layer using one dimensional (1D) material, which also provides flexibility of the LCs 6. However, these non-contact methods suffer from alignment instability because of their variable anchoring energy 5. To solve these problems, non-contact methods, such as ion-beam irradiation 3, 4 and the photo-alignment method 2, have been introduced. However, the rubbing process has certain disadvantages, including the accumulation of electrostatic charge, debris and local defects caused by contact with the roller 2. To produce high-quality display devices for commercial applications, a mechanical rubbing process on polyimide (PI) layers has been widely used to produce microgrooves that are capable of aligning LC molecules in a homogeneous or homeotropic orientation 1. The uniform alignment of liquid crystal (LC) molecules in a single direction has become an important subject of interest and is a core technological requirement for the fabrication of flexible displays.
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