Laser structuring of parallel electrode array on graphene/glass substrates for rapid inspections of moisturizing efficacy

This research aims to structure thin layers of graphene materials for impedance sensing chips with a parallel electrode array and to investigate the interaction between nanosecond pulsed Nd:YVO₄ lasers and graphene films coated on glass substrates. The optimal laser structuring conditions consisted of pulse repetition rate of 100 kHz, the scanning speed of two galvano scanners of 600 mm/s, the laser fluence of 3.4 J/cm², and parallel lines of the laser processing path with the line-scan spacing of 1 μm in one-cycle process to produce the parallel electrode structures. The surface morphology, cross-sectional profile, optical spectra, and material characterizations on graphene/glass substrates were detected by a confocal laser scanning microscope, a scanning electron microscope (SEM), a spectrophotometer, and a Raman spectroscopy, respectively. The parallel electrode sensing chips had been successfully used to detect the moisturizing efficacy of solutions containing moisturizers with 0, 3, 6, and 9 wt% 1,3-Butylene Glycol concentrations. The experimental results showed that the electrochemical impedance spectroscopy combined with graphene sensing chips had high sensitivity and saving time than weight loss of solutions detected by the precision electronic balance.