Optimizing the accuracy of viscoelastic characterization with AFM force-distance experiments in the time and frequency domains.
Optimizing the accuracy of viscoelastic characterization with AFM force-distance experiments in the time and frequency domains.
复制标题
通过时域和频域中的 AFM 力距实验优化粘弹性表征的准确性。
DOI：
10.1039/d2sm01331b
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发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
S. Solares
中科院分区：
文献类型：
--
作者：
Marshall R. McCraw;Berkin Uluutku;Halen D. Solomon;Megan S. Anderson;Kausik Sarkar;S. Solares
原子力显微镜(AFM)力-距离(FD)实验因其在具有广泛力学性能的材料中的广泛用途而成为传统微观流变学测量技术的一种有吸引力的替代方法。在这里，我们表明，从典型的FD反演方法(将本构FD关系与FD数据进行拟合)可以可靠地解决的时间依赖行为的范围内在地受到实验参数的限制：采样频率、实验长度和应变率。具体地说，我们证明了违反这些限制可能会导致复模参数值的错误。对于复杂的材料，如细胞，其行为并不是事先具体了解的，这些参数的物理敏感性无法评估，并可能导致错误地将物理现象归因于违反这些限制的人工制品。我们使用信息论的论点来理解这些不一致的本质，并设计出可以从FD实验中可靠地获得的力学参数范围的限制。结果进一步表明，这些限制的性质取决于反演过程中使用的域(时间或频率)，其中时间域的限制远远大于频率域的限制。最后，我们通过对聚二甲基硅氧烷(PDMS)聚合物样品的分析，展示了如何使用这些限制来更好地设计FD实验，以针对材料行为的特定时间尺度。
Atomic Force Microscopy (AFM) force-distance (FD) experiments have emerged as an attractive alternative to traditional micro-rheology measurement techniques owing to their versatility of use in materials of a wide range of mechanical properties. Here, we show that the range of time dependent behaviour which can reliably be resolved from the typical method of FD inversion (fitting constitutive FD relations to FD data) is inherently restricted by the experimental parameters: sampling frequency, experiment length, and strain rate. Specifically, we demonstrate that violating these restrictions can result in errors in the values of the parameters of the complex modulus. In the case of complex materials, such as cells, whose behaviour is not specifically understood a priori, the physical sensibility of these parameters cannot be assessed and may lead to falsely attributing a physical phenomenon to an artifact of the violation of these restrictions. We use arguments from information theory to understand the nature of these inconsistencies as well as devise limits on the range of mechanical parameters which can be reliably obtained from FD experiments. The results further demonstrate that the nature of these restrictions depends on the domain (time or frequency) used in the inversion process, with the time domain being far more restrictive than the frequency domain. Finally, we demonstrate how to use these restrictions to better design FD experiments to target specific timescales of a material's behaviour through our analysis of a polydimethylsiloxane (PDMS) polymer sample.
影响因子：
2
作者：
Thomas Peters
通讯作者：
Thomas Peters