Fabrication of soft gold microelectrode arrays as probes for scanning electrochemical microscopy

Soft linear gold microelectrode arrays for high throughput scanning electrochemical microscopy (SECM) imaging were fabricated using the Aerosol Jet® printing technology. Nanoparticulate gold ink was printed on polyimide Kapton HN® thin films. After sintering, a 200 nm thick Parylene C coating was deposited to cover and seal the gold tracks. A cross-section of the array of microelectrodes was exposed by laser cutting using an ArF excimer laser beam directed onto a metallic mask. Cyclic voltammograms, approach curves and SECM images in feedback mode demonstrate the capability of the arrays as SECM probes. Reactivity imaging of a platinum band structure on glass was performed with Parylene C coating facing the substrate providing an almost constant working distance. The softness of the array leads to a bending and allows scanning in contact mode like brushing the sample surface. For hard surfaces such as array electrode structures and similar materials, this occurs without detectable damage to the sample.