红外与激光工程, 2018, 47 (12): 1226003, 网络出版: 2019-01-10  

端面不透光的PDMS微柱阵列制备与图像处理方法研究

Research of preparation and image processing method of PDMS micropost arrays with opaque top surfaces
作者单位
北京信息科技大学 光电测试技术北京市重点实验室, 北京100192
摘要
细胞可对外界施加力的作用, 从而感知外界环境并做出力学响应。聚二甲基硅氧烷(PDMS)微柱阵列被广泛应用于细胞力测量, 通过测量微柱顶面在细胞力作用下的位移量, 获得细胞力的大小及方向。然而, 由于PDMS微柱的高透明度, 当利用明场显微图像进行图像处理计算微柱位移量时, 提取微柱端面质心的算法较为复杂。提出了一种利用磁珠修饰微柱端面使其不透光的方法, 以降低图像处理算法复杂度, 同时提高微柱位置的识别精度。磁珠在外界磁场作用下被引入模具, 向模具中浇铸PDMS后, 得到端面嵌有磁珠的不透光PDMS微柱。修饰过后的微柱, 其端面会在倒置显微镜下形成实心圆形图案, 可以直接用regionprops函数计算出实心圆形图案的质心; 未经修饰的微柱, 在倒置显微镜下形成环形图案, 需要用运算更为复杂的霍夫变换来计算环形图案质心。实验结果表明: 该PDMS微柱修饰方法能使微柱端面与基底的对比度得到很大提高, 因此在提取端面质心时, 不需要用到霍夫变换, 减小了图像处理中算法的复杂度, 并且提高了微柱定位的精度。
Abstract
Cells use force as a mechanical signal to sense and respond to their microenvironment. To this end, PDMS micropost arrays has been widely used in cell traction force measurement, which allows calculating magnitude and direction of cell force from the deflection of the micropost. However, the inherent transparency of PDMS leads to the complexity of image processing algorithm when retrieving the top surfaces centroids of the deflected microposts. A method of modifying the top surfaces of PDMS microposts using magnetic beads was proposed to attain opaque top surface of the micropost, enabling a higher contrast between the top surface and the substrate of the micropost array. Magnetic beads were brought into the molds by applying a magnetic field and casted in the PDMS microposts during soft-lithography process. The modified micropost arrays with opaque top surfaces were imaged using an inverted microscope as disk-shaped patterns top surface. The centroids of disk-shaped patterns in the microscopic image were calculated using regionprops function, while Hough transform was required to process the ring-shaped patterns of the conventional transparent microposts made with pure PDMS. The experimental results show that the contrast between the top surface and the substrate is significantly improved, hence precluding the need of using Hough transform, reducing the algorithm complexity in image processing, and improving the precision of micropost positioning.

李波, 董明利, 张帆. 端面不透光的PDMS微柱阵列制备与图像处理方法研究[J]. 红外与激光工程, 2018, 47(12): 1226003. Li Bo, Dong Mingli, Zhang Fan. Research of preparation and image processing method of PDMS micropost arrays with opaque top surfaces[J]. Infrared and Laser Engineering, 2018, 47(12): 1226003.

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!