基于激光直写的柔性电阻抗成像传感器研究

Flexible Electrical Impedance Imaging Sensor Based on Laser Direct Writing

基于柔性导电薄膜的电阻抗成像技术能够实现对外界刺激的二维可视化传感,在结构健康监测、人机交互、人体体征监测等领域具有广泛的应用前景。然而,现有的柔性导电薄膜多采用喷涂、浸涂和填充等方法来制备,需获取均匀分散导电浆料、且步骤较为复杂。采用激光直写技术这一高效、可规模化的加工方法,制备了一种新型柔性石墨烯导电薄膜用于电阻抗成像技术。通过调节激光焦点偏距优化了石墨烯传感器的电学性质各向异性。基于激光直写的柔性石墨烯电阻抗传感器可以用于空间裂纹、空间圆孔和筒体撞击的损伤监测。研究结果表明:该传感器可以实现空间损伤监测,最大定位误差为5.3%,最小面积比例估计误差为8.3%,在结构健康监测领域具有广阔的应用前景。

Electrical impedance tomography(EIT)based on flexible conductive film has the capability to visually demonstrate external stimuli in a two-dimension manner,showing the potentials in structural health monitoring,human-machine interface,and human health monitoring.So far,the method to develop the conductive film for EIT is through spraying,dip-coating,and injection of conductive materials,in which the procedure to obtain the conductive ink is necessary and complicated.Regarding this,laser direct writing,a high-efficient and scalable method,is developed to fabricate graphene-film based EIT sensor.Through the precise control of the laser focus offset and the electrical properties anisotropy of the graphene is optimized.Then,the graphene-based EIT sensor is applied to monitor spatial cracks,spatial circular holes and impact damage.The results show that the sensing film can realize spatial damage monitoring,the maximum positioning error is 5.3%,and the minimum area ratio estimation error is 8.3%,which has a prospect in the field of structural health monitoring.