光刻法制备正方薄片状粒子及其识别算法优化

Fabricating of Square Thin Particles by Lithography and Optimization of Recognition Algorithm

非球形胶体粒子在凝聚态物理、新型智能材料研发等领域均具有重要的研究价值,其中,正方薄片状胶体粒子由于具有形状简单、可周期性密铺、自组装形成的结构多样等特点,得到了广泛关注。采用光刻法制备了SU-8环氧树脂正方薄片状胶体粒子,粒子的平均边长为2.3μm、平均厚度为1.2μm,顶点在光刻精度影响下,发生小幅度圆角化。通过分析光刻前后粒子的红外吸收光谱发现,光刻后,粒子内部的SU-8环氧树脂交联程度较高。通过计算粒子相互作用势与粒子间距离的关系,证明了粒子间的相互作用为近硬球相互作用。同时,基于正方薄片状胶体粒子在平面及球面的单粒子运动图像,提出了一种新的粒子顶点识别算法,该算法可以避免由图像不清晰导致的粒子错误识别问题。

Non-spherical colloidal particles had important research value in fields such as condensed matter physics and the development of new intelligent materials.Among them,square thin colloidal particles,which could be periodically and densely packed,had attracted widespread attention due to their simple shape,and diverse self-assembled structures.The material of the square thin colloidal particles prepared by photolithography was SU-8 epoxy resin.The side length of the particles was 2.3μm and the thickness of the particles was 1.2μm.Vertices were slightly rounded due to the influence of lithography accuracy.By analyzing the infrared absorption spectra of particles before and after photolithography,it was found that,after photolithography,the cross-linking degree of SU-8 epoxy resin inside the particles was relatively high.By calculating the relationship between the interaction potential of particles and the distance between particles,it was proven that the interaction between particles was a near hard-sphere interaction.Furthermore,a new particle vertex recognition algorithm was proposed based on the single-particle motion images of the square thin colloidal particles on both planar and spherical surfaces,which could avoid particle misrecognition problems caused by unclear images.