摘要
The emerging technique of carbonization of polyimide(PI)by direct laser writing receives great attention for its flexibility,versatility,and ease-of-patterning capability in creating a variety of functional laser-induced graphene(LIG)sensors and devices.LIG prepared by CO_(2) laser irradiating of the PI film is characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),transmission electron microscope(TEM),specific surface area analyzer,synchronous thermal analysis,and Raman spectroscopy with the focus on investigating the effects of laser parameters(e.g.,power,scanning speed)on the microstructure,thickness,and sheet resistance of LIG.Both TEM and XRD indicate that LIG is composed of many graphene layers with a layer spacing of 0.34 nm.The specific surface area of LIG decreases with the increase of laser power.The ratio of the thickness of LIG over the depth of the carbonized PI film as the expansion ratio characterizes the expansibility of LIG.The influence of image resolution and off-focus value on the sheet resistance of LIG is explained by the superposition mechanism of laser scanning spots.
基金
supported by the National Natural Science Foundation of China(Grant No.51705082)
the State Key Laboratory of Digital Manufacturing Equipment and Technology
Huazhong University of Science and Technology(Grant No.DMETKF2021013)
the supports provided by the National Science Foundation(NSF)(Grant No.ECCS-1993072)
the American Chemical Society Petroleum Research Fund(59021-DNI7)
the National Heart,Lung,and Blood Institute of the National Institutes of Health(Grant No.R61HL154215)
Penn State University。
