Probing The Elasticity Of Biological Samples With The At

原子力显微镜（AFM）正日益成为在微观尺度上测量材料性能的一线工具。然而，当涉及到像细胞这样的软生物材料时，实验技术和数据分析的问题仍然存在。我们开发了基于材料各向同性和均匀性假设的薄软样品的方法。然而，根据兴趣的大小，大多数生物系统可能两者都不是。我们正在进一步开发实验技术，以确定获取数据所需的测量类型，这些数据将允许在材料各向异性的情况下进行详细的材料表征。同时，我们正在开发相应的接触问题的理论模型，用于分析实验数据。我们的动机是在体外测量毡膜（TM）的材料参数，以确定其在哺乳动物耳蜗中发生的机械过滤和放大中的作用。TM是一种胶原膜，电镜显示其具有很强的各向异性纤维组织。这种纤维的各向异性模式被怀疑在决定TM的机械响应中起重要作用，包括局部、立体纤毛附着和全局。

The atomic force microscope (AFM) is increasingly becoming a first line tool for measuring material properties at microscopic scales. When it comes to soft biological materials such as cells, however, issues with experimental techniques and with data analysis remain. We have developed methodologies for thin, soft samples based on the assumption of material isotropy and homogeneity. Most biological systems, however, depending on the scale of interest may be neither. We are developing experimental techniques further to establish the types of measurements needed to acquire data that would allow detailed material characterization in the case of material anisotropies. In parallel, we are developing theoretical models for the corresponding contact problems which are being used to analyze experimental data. Our motivation is to measure the material parameters of the tectorial membrane (TM) in-vitro in order to establish its role in the mechanical filtering and amplification that occur in the mammalian cochlea. The TM is a collagenous membrane which has been shown by electron microscopy to have strongly anisotropic fiber organization. This anisotropic patterning of the fibers are suspected to play an important role in determining the mechanical response of the TM, both locally, at the stereociliary attachments and globally.