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柔性压力传感器由于可以贴附在各种不规则物体的表面，引起人们广泛的研究兴趣，但实际应用中如何实现调控电阻式压力传感器的灵敏度和响应范围仍是一个挑战。针对这一问题，在传感器表面设计了不同尺寸和密度分布的金字塔结构，用于有限元分析和实验研究。结果表明，初始接触面积对灵敏度有较大影响，而传感器表面的微结构密度和尺寸对响应范围有较大影响。利用这个设计策略，在基于聚二甲基硅氧烷(PDMS)弹性材料和多壁碳纳米管(MWCNT)/PDMS导电复合材料的柔性传感器表面设计了低密度金字塔微结构，该传感器在0～0.31 kPa的范围内具有很高的灵敏度(17.61 kPa-1)。改变金字塔微结构的尺寸和密度，当传感器表面结构的高度和间距分别为80μm和160μm时，该传感器可以在0～0.74 kPa的较大压力范围内具有4.77 kPa-1的较高灵敏度。此外，该传感器还具有良好的可重复性和稳定性，在经超过1 000次的压力加载-卸载循环后传感性能仍保持稳定。在应用方面，该传感器可以准确地识别手指触摸产生的微小压力信号，可适用于具有生物相容性材料系统和灵活舒适的医疗保健可穿戴电子产品。
Abstract：Flexible pressure sensors can be conformably attached to the surfaces of various irregular objects, so have attracted extensive research interest. However, it is still challenge to adjust the sensitivity and response range of resistive pressure sensors in practical uses. To solve the problem, a pyramid structure with different sizes and density distributions was designed on the sensor surface for finite element analysis and experimental research. The results show that the initial contact area has substantial effects on the sensitivity, while the microstructure density and size of the sensor surface have a great influence on the response range. Using the design strategy, a low density pyramid microstructure was designed on the surface of a flexible sensor based on polydimethylsiloxane(PDMS) elastic material and multiwall carbon nanotubes(MWCNTs)/PDMS conductive composite material. The sensor has a high sensitivity(17.6 kPa-1) in the range of 0-0.31 kPa. By varying the size and density of the pyramid microstructure, the sensor can have higher sensitivity of 4.77 kPa-1 through the large pressure range of 0-0.74 kPa when the height and spacing of the sensor surface structures are 80 μm and 160 μm, respectively. In addition, the flexible resistive pressure sensors are highly reproducible and stable, the sensing performance remains stable after more than 1 000 times pressure load-unload cycles. In application, the sensors can accurately identify tiny pressure signals generated by finger touch, is suitable for wearable electronics for health care with the biocompatible material systems and flexible comfort.
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基本信息:
DOI：10.13250/j.cnki.wndz.2023.07.013
中图分类号:TP212
引用信息:
[1]王海军,李飞,杨云鹏,等.基于微结构的柔性压力传感器的界面设计对传感性能的影响[J].微纳电子技术,2023,60(07):1094-1101.DOI:10.13250/j.cnki.wndz.2023.07.013.