基于石墨烯/PEDOT:PSS复合材料制备的可穿戴柔性传感器

Flexible wearable sensor based on graphene/PEDOT:PSS composite material

随着智能设备的普及,可穿戴电子设备呈现出巨大的市场前景.电阻式柔性应变传感器因具备较高的灵敏度与良好的生物兼容性等优点使其成为受关注的电学传感器.本文基于溶液共混法,制备一种新型的石墨烯(GR)/PEDOT:PSS多组分混合墨水材料,用直写喷墨打印技术制备了“电阻式”柔性应变传感器.该传感器以聚酰亚胺(PI)柔性薄膜为基底材料,以GR/PEDOT:PSS多组分混合墨水为导电材料,通过直写喷墨打印技术在柔性基底上打印导电图形.实验利用SEM、电学测试平台等表征手段分析了不同的GR掺加量对复合墨水材料性能与打印工艺的影响.实验结果表明:采用乙醇超声分散的GR材料可有效分布在PEDOT:PSS中,进而改善其在导电聚合物中的分散性;提高打印速率可明显降低线宽;随着GR掺加量的增大,柔性传感器阻值逐渐降低,器件的灵敏度下降;由此推断出相对疏松、分散性较好的墨水材料更有利于灵敏度的提高;提高柔性传感器的深宽比,可显著提高传感器的灵敏度.当弯折角度为80。时,电阻变化率(R/R。)最高为3.414,有望应用于柔性可穿戴设备新兴领域.

As a rapidly emerging field for the intelligent terminals, wearable electronic devices have present a huge market prospect. Flexible resistive strain sensor has become one of the most concerned electrical sensors owing to its attractive properties, such as high sensitivity and biocompatibility. In this paper, a novel graphene (GR)/PEDOT:PSS multi-component hybrid ink material was prepared based on solution blending method. A "resistive" flexible strain sensor was fabricated by direct-inkjet printing technology. Polyimide (PI) flexible film, and GR/PEDOT:PSS multi-component mixed ink were used as substrate and conductive material, respectively. The conductive patterns were printed on the flexible substrate by direct-inkjet-printing technology. The scanning electron microscope (SEM) and electrical test platform were used to characterize and analyze the effect of different graphene doping amounts on the performance and printing process of composite ink materials. The experimental results show that the GR material dispersed by ethanol can be effectively distributed in PEDOT:PSS, which improves its dispersibility in conductive polymer. The line width decreases as the print rate increases and the resistance and sensitivity of the flexible sensors are gradually decreased with the increase of GR doping amount. It can be concluded that the ink material with relatively loosened and dispersive property will be more conducive to improve the device sensitivity. The sensitivity of the flexible wearable sensor can be significantly improved with the increasing aspect ratio of the flexible sensor as well. The resistance change rate (RIRj is up to 3.414 when the bending angle was 80°, which makes the GR/PEDOT:PSS composite material based sensor promising to be applied in the emerging field of flexible wearable devices.