Near-Infrared Laser Direct Writing of Conductive Patterns on the Surface of Carbon Nanotube Polymer Nanocomposites

International audience; Near-infrared (NIR) laser annealing is used to write conductive patterns at the surface of Polypropylene/Multi-walled carbon nanotube nanocomposite (PP/MWCNT) plates. Before irradiation, the surface of the nancomposite is not conductive due to the partial alignment of the MWCNT which occurs during injection molding. We observe a significant increase of the surface sheet resistance using NIR laser irradiation, which we explain by a randomization of the orientation of MWCNTs in the PP matrix melt by NIR laser irradiation. After only 5s of irradiation, the sheet resistance of PP/MWCNT, annealed with a laser at a power density of 7 W/cm 2 , decreases by more than 4 decades from ~ 100 MΩ/sq to ~ 1 kΩ/sq. Polarized Raman, TEM, and SEM are used to investigate the changes in the sheet resistance and confirm the physico-chemical processes involved. This allows directwriting of conductive patterns using NIR laser at the surface of nanocomposite polymer substrates, with the advantages of a fast, easy, and low-energy consumption process.