Abstract
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•Laser ablation is used to prepare surface of laminate for electrical measurements.•Laser ablation provides better surface fiber exposure than sand polishing.•Optimal parameters for laser ablation is identified by Raman spectroscopy.•Electrodes produced on laser ablated surfaces show low and uniform contact impedance.•With laser ablation, contact impedance becomes independent of the electrode material.
Electrical impedance tomography (EIT) is a low-cost, fast and effective structural health monitoring technique that can be used on carbon fiber reinforced polymers (CFRP). Electrodes are a key component of any EIT system and as such they should feature low resistivity as well as high robustness and reproducibility. Surface preparation is required prior to bonding of electrodes. Currently this task is mostly carried out by traditional sanding. However this is a time consuming procedure which can also induce damage to surface fibers and lead to spurious electrode properties. Here we propose an alternative processing technique based on the use of pulsed laser irradiation. The processing parameters that result in selective removal of the electrically insulating resin with minimum surface fiber damage are identified. A quantitative analysis of the electrical contact resistance is presented and the results are compared with those obtained using sanding.