基于磁控取向银纳米线的柔性应变传感器制备及结构-传感性能关系研究

In recent years, the demand for flexible strain sensors is growing rapidly due to the science and technology progress. Depending on various application demands, the fabrication of corresponding optimized sensitivity and measurement range of strain sensors is of great importance and meanwhile it is also a big challenge in this field. Thus, it is scientifically meaningful and valuable to achieve the designable characteristic of flexible strain sensors. In this proposal, ordered microstructure will be obtained through accurately aligning and controlling of the 1D nano-fillers in the flexible matrix with an external magnetic field to achieve the quantitatively adjustment of the performance of the strain sensor, which is a novel and feasible approach. In detail, the magnetic field-controlled method will be utilized for creating the alignment of magnetic nanoparticles-coated silver nanowires (Ag-NWs) in PDMS matrix. The Ag-NW network structures with different alignment degrees can be obtained by controlling the external magnetic fields and the relative weight percentages of magnetic nanoparticles. By utilizing the probability distribution function and orientation tensor, we will obtain a series of preferential alignment degree (PAD) values for the Ag-NW network structures. Afterwards, the strain sensing properties will be measured, and the relationship between the structure parameters (such as PAD values, initial resistance, and areal density) and sensing performance including gauge factor, measuring range, response time and stability will be studied. Through this proposed research work, a referable theoretical model will be established for the design and manufacturing of high performance flexible strain sensors.

近年来，柔性应变传感器由于科技进步而发展迅速。根据不同应用需求，制造具有相应优化灵敏度和检测范围的传感器成为该领域的研究重点和挑战。因此，实现传感器性能的可设计性具有重要的科学意义和应用价值。本项目拟利用外加磁场对柔性基体中一维纳米填料进行精确取向和控制从而获得有序微结构网络，以达到定量调控传感器性能的目的，是一种新颖、有效的技术方法。具体地，在硅胶基体中利用外加磁场定向排列负载纳米磁性粒子的银纳米线，通过调控磁场强度和负载比例，得到具有不同取向度的银纳米线网络结构；利用概率分布函数和二阶取向张量，定量计算获得银纳米线网络的相对取向度PAD值；测试分析取向度与应变传感性能之间的关系和影响机理，得到几何结构参数（PAD值）、物理参数（初始电阻）、边界条件（面密度）与灵敏度、测量范围、响应时间及稳定性等各个变量之间的关系，拟合出可参考的理论模型，为开发高效且可设计的柔性应变传感器提供设计依据。

近年来，随着科技进步，柔性应变传感器发展迅速。依据应用需求的不同，制造得到具有相应优化灵敏度和检测范围的传感器成为该领域的开发重点和挑战。因此，对传感器性能进行针对性设计具有重要的科学意义和应用价值。本项目通过调控磁场强度和磁性粒子的负载比例，获得了具有有序微结构的银纳米线导电网络。随后选取PDMS作为基体，得到了具有不同银纳米线取向程度的柔性应变传感器。利用Fiji软件分析和二阶取向张量计算相结合的方法，定量表征了银纳米线网络的相对取向度PAD值。重点研究了银纳米线基柔性应变传感器的循环稳定性以及其在取向后对应不同取向度PAD时的应变传感性能。测试分析了取向度与应变传感性能之间的关系和影响机理，得到了几何结构参数（PAD值）、物理参数（初始电阻）、边界条件（面密度、包覆比例、磁场强度）与灵敏度、测量范围及稳定性等各个变量之间的关系，并分析了结构-性能的关系规律。研究成果可为高效且可设计的柔性应变传感器的开发做好技术准备，具有重要的研究参考价值。