纳米黏弹性测量中谐振抑制方法研究

Resonance Suppression on Nanoscale Viscoelasticity Measurement

针对压痕测量软材料中悬臂梁谐振导致测量数据存在较大误差的问题，提出一种在宽带纳米黏弹性测量中抑制悬臂梁谐振的方法。基于z轴动态特性设计一种陷波器类型的前置滤波器，并对输入驱动电压进行滤波；设计基于最小均方误差准则（LMS）的自适应滤波器，参考赫兹接触模型对软材料的复蠕变量进行滤波，进而在输入环节和测量环节消除谐振影响。通过二甲基硅氧烷（PDMS）样本的黏弹性测量实验，验证悬臂梁谐振抑制方法的有效性。

Aiming at the cantilever resonance leads to large measurement data errors in indentation measuring soft material, a method to suppress the cantilever resonance on the broadband viscoelasticity measurement is proposed. A notch filter type prefilter based on z-axis dynamics is designed, and used to filter the input drive voltage; An adaptive filter based on the least mean square （LMS） is designed, and referring to the Hertz contact model to filter the complex compliance of soft materials, furtherly eliminate the residual cantilever resonance effects in input link and output link. The validity of the cantilever resonance suppression method is verified by implementing the polydimethylsiloxane （PDMS） sample viscoelasticity measurement.