Effect of folded contact between electrode and dielectric layer on the performance of piezoelectric flexible electronic skin
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摘要: 提出了一种基于压电效应制备柔性电子皮肤的简单方法。为了研究纳米改性对柔性电子皮肤各层性能的影响,首先以纳米SiO2粒子作为改性体,以聚二甲基硅氧烷(PDMS)作为基体,制备出SiO2/PDMS复合柔性衬底,解决了在PDMS上磁控溅射沉积电极材料产生裂纹的现象,成功获得能够稳定工作的柔性电极。然后用钛酸钡/碳纳米管/聚二甲基硅氧烷(BaTiO3/CNTs/PDMS)复合材料作为功能层,制备出一种五层结构的高灵敏性柔性电子皮肤,并找到一种通过改变基板粗糙度的简单方法构建电极与介电层的褶皱接触,进而提升柔性电极的电导率与柔性电子皮肤的压电响应信号。Abstract: A simple method for fabricating flexible electronic skin based on piezoelectric effect was presented. In order to study the effect of nano modification on the performance of flexible electronic skin, SiO2/polydimethylsiloxane (PDMS) composite flexible substrate was prepared by using nano-SiO2 particles as modifiers and PDMS as matrix. The flexible and stable electrodes were prepared and the crack problem of electrode material on flexible PDMS substrate by magnetron sputtering was successfully solved. The functional layer of barium titanium trioxide/carbon nanotubes/PDMS (BaTiO3/CNTs/PDMS) was implanted in the five-layer structure of the flexible electronic skin that was designed based on the piezoelectric effect. A simple method by varying the substrate roughness was proposed to make a folded contact between the electrode and the dielectric layer. This method improves the conductivity and piezoelectric response of the prepared flexible electronic skin.
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Key words:
- magnetron sputtering /
- nano-SiO2 /
- flexible electronic skin /
- piezoelectric response /
- flexible sensor
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图 1 高灵敏度柔性电子皮肤结构示意图((a)褶皱电极在光学显微镜下单位面积(1 148 μm×856 μm);(b)粗糙聚二甲基硅氧烷(PDMS)在光学显微镜下单位面积(1 148 μm×856 μm);(c)介电层中BaTiO3与碳纳米管(CNTs)分布示意图;(d)扫描电镜下介电层表层形貌;(e)激光显微镜下介电层粗糙表面三维图像)
Figure 1. Layered structure of high sensitivity flexible electronic skin ((a) Foldable electrode images of the thin film per unit area (1 148 μm×856 μm) under light microscope; (b) Rough polydimethylsiloxane (PDMS) images of the thin film per unit area (1 148 μm ×856 μm) under light microscope; (c) Distribution diagram of BaTiO3 and carbon nanotubes (CNTs) in dielectric layer; (d) Surface morphology of dielectric layer under scanning electron microscope; (e)Three-dimensional image of rough surface of dielectric layer under laser microscope)
图 4 分别在120 W、100 W、80 W、60 W功率下溅射沉积在PDMS上的铜薄膜在光学显微镜下单位面积(1 148 μm × 856 μm)的裂纹情况(图片右上角标注的是PDMS衬底中纳米SiO2的质量分数,(a)、(b)、(c)载物台为硅片,(d)载物台为Cu片)
Figure 4. Crack images of the copper thin film on PDMS per unit area (1 148 μm × 856 μm) under light microscope, respectively, for the magnetron sputtering power of 120 W, 100 W, 80 W and 60 W (At the top right of the picture is the mass fraction of nano SiO2 in PDMS substrate, (a), (b), (c) silicon platform, and (d) Cu platform)
表 1 介电层实验材料及比例
Table 1. Dielectric layer experimental material and proportion
Material Quality/g Source of materials PDMS 10.0 Dow corning BaTiO3 6.0 Aladdin CNTs/C2H6O 0.5 Aladdin -
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