Optimal Excitation Force Design in Indentation-Based Rapid Broadband Nanomechanical Spectroscopy: Poly(dimethylsiloxane) Example
Optimal Excitation Force Design in Indentation-Based Rapid Broadband Nanomechanical Spectroscopy: Poly(dimethylsiloxane) Example
复制标题
基于压痕的快速宽带纳米机械光谱的最佳激发力设计：聚（二甲基硅氧烷）示例
DOI：
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发表时间：
2013
影响因子：
4.8
通讯作者：
Q. Zou
中科院分区：
文献类型：
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作者：
Zhonghua Xu;Q. Zou
提出了一种基于压痕法的软材料宽带纳米力学快速测量的最优输入设计方法。基于压痕的纳米力学测量提供了在指定位置处的材料特性的独特量化。然而，该测量目前太慢且频率（范围）太窄，无法表征动态演变期间随时间推移的材料性质（例如，聚合物结晶过程的快速阶段）。存在这些限制是因为当前方法中使用的激励输入力无法快速激发材料的宽带纳米力学性能。当激振力中的频率增加时，仪器硬件动态特性在测量过程中被激发并与材料特性卷积，从而导致大的测量误差，因此出现了挑战。此外，当频率范围大时，测量花费长时间，这又导致在样品的动态演变时的大的时间测量误差。在本文中，我们开发了一种最优输入设计方法来应对这些挑战。特别地，具有离散谱的输入力分布被优化以最大化软材料的线性柔度模型的Fisher信息矩阵。聚（二甲基硅氧烷）（PDMS）样品的模拟和实验，以说明需要最佳的输入设计和所提出的方法在基于探针的纳米力学性能测量的功效。
This paper presents an optimal input design approach to achieve rapid broadband nanomechanical measurements of soft materials using indentation-based method. The indentation-based nanomechanical measurement provides unique quantification of material properties at specified locations. The measurement, however, is currently too slow and too narrow in frequency (range) to characterize time-elapsing material properties during dynamic evolutions (e.g., the rapid-stage of the crystallization process of polymers). These limitations exist because the excitation input force used in current methods cannot rapidly excite broadband nanomechanical properties of materials. The challenges arise as a result of the instrumental hardware dynamics being excited and convoluted with the material properties during the measurement when the frequencies in the excitation force increase, resulting in large measurement errors. Moreover, measurement takes a long time when the frequency range is large, which, in turn, leads to large temporal measurement errors upon dynamic evolution of the sample. In this paper, we develop an optimal-input design approach to tackle these challenges. Particularly, an input force profile with discrete spectrum is optimized to maximize the Fisher information matrix of the linear compliance model of the soft material. Both simulation and experiments on a Poly(dimethylsiloxane) (PDMS) sample are presented to illustrate the need for optimal input design and the efficacy of the proposed approach in probe-based nanomechanical property measurements.