AZO Embedded Interdigitated Electrodes for Monitoring Stimuli Responsive Materials

Abstract A combination of atomic layer deposition and photolithography is applied to fabricate interdigitated electrodes of aluminum‐doped zinc oxide embedded in polyethylene terephthalate substrates. Various designs with different gap to widths ratios are realized and important characteristics of the electrodes, including thickness, surface roughness, and electrical properties with different ZnO:Al 2 O 3 ratios are studied. Oxygen plasma is applied to etch the polyethylene terephthalate surface and to embed the electrodes, a methodology which is a breakthrough toward ultimately thin devices fabrication. Moreover, the influence of oxygen plasma on the electrical properties of aluminum‐doped zinc oxide is analyzed in more detail. Electrochemical impedance spectroscopy studies of two different stimuli responsive ionogels are performed using the fabricated electrodes. The results show the suitability of the use of the fabricated electrodes to monitor changes in ion motion and morphology of stimuli responsive materials. These electrodes and the process of characterization of the ionogels presented could be implemented to monitor electrochemical changes in real applications such as protective coatings.