Determination of elastic moduli of thin layers of soft material using the atomic force microscope
Determination of elastic moduli of thin layers of soft material using the atomic force microscope
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DOI：
10.1016/s0006-3495(02)75620-8
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发表时间：
2002-05-01
影响因子：
3.4
通讯作者：
Chadwick, RS
中科院分区：
文献类型：
--
作者：
Dimitriadis, EK;Horkay, F;Chadwick, RS
我们解决了三个问题，限制了使用原子力显微镜测量弹性模量的软材料在微观尺度。第一个问题是使用尖锐的悬臂尖端，这通常会引起远远超过线性材料制度的局部应变。我们表明，这个问题可以通过使用微球作为探针来缓解，我们建立了使用它们的标准。第二个问题涉及到赫兹接触力学模型的普遍使用，这导致了显着的错误时，适用于薄样品。我们开发了新颖的，简单易用的校正来应用于此类情况。考虑粘结或未粘结到刚性基底的样品。第三个问题涉及当接触发生在软材料上时难以建立。我们得到的弹性模量的误差估计，从这样的不确定性，并讨论了接触点的误差的估计方法的敏感性。的理论和实验结果进行了比较宏观测量聚（乙烯醇）凝胶。
We address three problems that limit the use of the atomic force microscope when measuring elastic moduli of soft materials at microscopic scales. The first concerns the use of sharp cantilever tips, which typically induce local strains that far exceed the linear material regime. We show that this problem can be alleviated by using microspheres as probes, and we establish the criteria for their use. The second relates to the common use of the Hertz contact mechanics model, which leads to significant errors when applied to thin samples. We develop novel, simple to use corrections to apply for such cases. Samples that are either bonded or not bonded to a rigid substrate are considered. The third problem concerns the difficulty in establishing when contact occurs on a soft material. We obtain error estimates for the elastic modulus resulting from such uncertainty and discuss the sensitivity of the estimation methods to error in contact point. The theoretical and experimental results are compared to macroscopic measurements on poly(vinyl-alcohol) gels.