Ahmadi Nima, Fathalilou Mohammad, Rezazadeh Ghader
Department of Mechanical Engineering, National University of Skill (NUS), Tehran, Iran.
Mechanical Engineering Department, Urmia University, Urmia, Iran.
Sci Rep. 2024 Oct 25;14(1):25428. doi: 10.1038/s41598-024-76528-1.
In the contemporary era, the enhancement of wearable capacitive sensors is achieved through the utilization of polymeric micropillars as filler materials between electrode plates. To gain a deeper understanding of the dynamic response of the system, nonlinear coupled governing equations of a circular microplate motion resting on an array of polymeric micropillars have been derived. These equations are used to model the system's behavior. In addition, the squeezing motion of the micro-pillars is characterized using the incompressible Neo-Hookean model. Both static and dynamic responses, including transient and steady-state solutions, are investigated in detail by discretizing over spatial coordinates using a weak formulation approach. A frequency response analysis is conducted using a continuation-based method. This entails expanding the steady-state solution using a Fourier transform and employing the energy balance principle. The unknown coefficients of the expansion series are calculated using a gradient descent-based learning approach that is physically motivated. Furthermore, a dynamic step size strategy for frequency increments is employed to effectively follow the solution path. This strategy is implemented via the ARC length method. In this study, we examine the impact of varying PDMS (polydimethylsiloxane) hydrogel mechanical and geometrical configurations. It can be reasonably concluded that the mechanical properties of the pillars and the geometrical configuration of the circular plate and micropillars have a significant impact on the maximum tolerable pressure, fast transient response, and frequency response analysis.
在当代，可穿戴电容式传感器的性能提升是通过将聚合物微柱用作电极板之间的填充材料来实现的。为了更深入地了解该系统的动态响应，推导了置于聚合物微柱阵列上的圆形微板运动的非线性耦合控制方程。这些方程用于对系统行为进行建模。此外，使用不可压缩的新胡克模型来描述微柱的挤压运动。通过使用弱形式方法在空间坐标上进行离散化，详细研究了包括瞬态和稳态解在内的静态和动态响应。使用基于延拓的方法进行频率响应分析。这需要使用傅里叶变换展开稳态解并采用能量平衡原理。展开级数的未知系数使用基于物理动机的基于梯度下降的学习方法进行计算。此外，采用了一种用于频率增量的动态步长策略来有效地跟踪求解路径。该策略通过弧长法实现。在本研究中，我们研究了不同聚二甲基硅氧烷（PDMS）水凝胶力学和几何构型的影响。可以合理地得出结论，柱体的力学性能以及圆形板和微柱的几何构型对最大耐受压力、快速瞬态响应和频率响应分析有显著影响。
