High-throughput scanning electrochemical microscopy brushing of strongly tilted and curved surfaces

The feasibility of high-throughput scanning electrochemical microscopy (SECM) of strongly tilted (tilt angles ≤4°) and curved substrates (diameter of curvature ≥9 cm) is demonstrated by brushing them with a soft linear array of carbon microelectrodes. This probe made of thin polymeric layers operates in contact regime to follow the topography of highly unconventional SECM samples while keeping an almost constant working distance. Strong slope variations of the sample lead to a slight misalignment between the axes of the positioning system and the sliding direction of the microelectrode arrays. The resulting positional offsets can be predicted and corrected to yield a correct representation of the spatial relation on the surface of the sample. Moreover, a custom-made holder system ideally suited for precise control of the soft probe inclination angle and alignment with the substrate plane was also developed to perform high-throughput SECM imaging of a 1.2 cm2 curved metallic pin within less than 2 h.