弹性培养膜力学性能的相移影栅云纹法测试(英文)

Mechanical property of elastic culture membrane using phase-shift shadow moiré method

背景：细胞附着在生物硅胶膜上，在机械顶压作用下，细胞会随着培养膜伸张发生形变，从而可以观察其在不同外力作用下的生长规律，但是，培养膜各部分受力情况如何？目的：用光力学实验方法得出培养膜的离面位移，进而求出生物硅胶膜的应变分布。设计、时间及地点：对比观察实验，于2008-03/08在上海应用技术学院机械与自动化工程学院光测力学实验室完成。材料：将美国道康宁公司生产的医用硅橡胶Q7—4750模压成圆形薄膜，直径为100mm，厚度为150-160μm，弹性模量2．14MPa，泊松比为0．48。方法：运用相移影栅云纹法。光源采用点光源：栅板采用5线，mm的玻璃栅板，夹持在平移相移机构上，相移机构每次手动5刻度，栅板移动0．1mm，以产生相移图，CCD摄像机被用来进行采集云纹图，并直接输入电脑，利用专用图像处理软件进行位相计算和位相解包裹，最后根据相位与位移关系，将相位转换成位移，可得到三维形貌。主要观察指标：离面位移信息。培养膜的变形量（包括位移和应变）。结果：利用采集的云纹图，通过相移方法，对4种球冠加载后的培养膜三维形貌利用图像处理重建，得到了培养膜各点的离面高度，对应于1％，10％，20％，25％的应变量，最高点分别为2.28，8．32，12．12，13．52mm，重建培养膜形貌矢径高与已知球缺矢径高误差315％，表明该实验方法精度较高；通过离面高度计算了沿径向由张力引起的应变，其结果呈抛物线型。结论：通过将影栅云纹法应用于细胞培养膜的力学性能测试，得到了培养膜的各个部分的位移分布为等高线分布形式，即培养膜中心部位移最大，应变沿培养膜对称轴呈抛物线形。

BACKGROUND： Under the pressure of mechanical action, the culture membrane will be stretched and cause the deformation of cells which adhere to the surface of culture membrane. According to this, growth regularity in different external force environments will be observed; however, how to determine the load distributions on the whole culture membrane still remains unclear. OBJECTIVE： Photomechanics method was applied for determining the out-plane displacement so as to obtain the strain distributions of the cell culture membrane. DESIGN, TIME AND SETTING： Contrast study was performed at the Photomechanics Laboratory, School of Mechanical and Automation Engineering, Shanghai Institute of Technology from March to August 2008. MATERIALS： Culture membrane which specially used for biomedicine was made by Dow Coming Corporation, USA and the type was Q7-4750. The dimension and mechanics properties were as follows： diameter = 100 mm, thickness = 150-160μ m, modulus of elasticity E = 2.14 MPa, and Poison＇s ratio = 0.48. METHODS： Shadow moir6 method with phase shift was used for the experiment. Light resource was sodium light; grid plate was 5 lines per millimeter; phase shift set was controlled by manual and 5 marks equal 0.1 mm; CCD camera was used for capturing moir6 patterns. Finally, phase was transformed into displacement so as to obtain three-dimensional appearance and manner. MAIN OUTCOME MEASURES： Out-plane displacement information, and deflection of culture membrane including displacement and strain. RESULTS： The three-dimensional profiles of culture membrane after deformation were constructed by image processing method and the out-plane heights could be obtained. Corresponding to the total strains of 1%, 10%, 20%, and 25% for the culture membrane, the displacement of highest point was 2.28 mm, 8.32 mm, 12.12 mm, and 13.52 mm, respectively. The error was 3.5% through comparing the measured heights of culture membrane with the heights which was known for the culture membrane. It indicated that this experiment method was highly sensitivity. According to the out-plane displacements, the strains distributions along symmetrical axis were calculated and the distributions of strain were shown by parabolic curve. CONLUSION： Through applying the shadow moire method for measuring mechanical behaviors of culture membrane, the displacement distributions of culture membrane is obtained and shown displacement contour. Namely, the out-plane displacement of center for the membrane has the maximum heights, and the strains distributions are shown parabolic curve.