基于BiCl_(3)/P(VDF-TrFE)膜的柔性压力传感器设计及其在力感知键盘中的应用

Design of flexible nano pressure sensor based on BiCl_(3)/P(VDF-TrFE)composite film and application in force sensing flexible keyboard

静电纺丝法制备有机压电传感器较传统压力传感器具有更好的柔韧性、轻质且透气,在可穿戴传感器研究领域中备受关注。本文提出了一种以静电纺丝工艺制备氯化铋/聚偏氟乙烯-三氟乙烯(BiCl_(3)/P(VDFTrFE))复合膜的方法,并以该复合膜为功能层,设计并制备了柔性压电传感器。一定含量BiCl_(3)加入后,扫描电子显微镜分析结果表明纤维平均直径从619 nm增至1158 nm,且表面更趋光滑,XRD结果证实复合膜的β相含量得到了明显提高。压电响应测试结果显示,BiCl_(3)含量为2wt%的P(VDF-TrFE)复合膜开路峰峰值电压和短路电流分别为16.8 V、164 nA,相比纯P(VDF-TrFE)压电薄膜有明显提升,是其2.15倍和2.24倍。压力感知实验显示,在1.28 N的按压力以下,具有较好的线性输出特性,并展现了良好的稳定性和重现性。利用该薄膜设计了柔性可穿戴力感知键盘,该键盘能采集用户的按压力度和持续时间,为柔性键盘等智能织物等相关应用提供了参考。

The organic piezoelectric sensor prepared by electrospinning is better flexibility,light weight and breathability than the traditional pressure sensor,which has attracted much attention in the field of wearable sensor research.In this paper,a method of preparing BiCl_(3)/poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE))composite film by electrospinning was proposed,and the flexible piezoelectric sensor was designed and prepared with the composite film as the functional layer.After a certain amount of BiCl_(3)is added,the scanning electron microscope analysis shows that the average diameter of the fiber increases from 619 nm to 1158 nm,and the surface becomes smoother.The X-ray diffraction pattern confirms thatβphase content of the composite film has been significantly improved.The piezoelectric response testing results show that the open circuit peak-to-peak voltage(Voc)and short-circuit current(Isc)of P(VDF-TrFE)composite films with 2wt%BiCl_(3)are 16.8 V and 164 nA.Compared with pure P(VDF-TrFE)piezoelectric film,it is obviously improved 2.15 and 2.24 times.The pressure sensing testing results show that the piezoelectric film is good linear output characteristics under the pressure of 1.28 N.A flexible wearable force sensing keyboard was designed with this film,which could collect fingers pressing force and duration time.And it provides a reference solution on smart fabrics such as flexible keyboard applications.