Interdigitated array 3D micromesh electrodes for electrochemical sensors

This paper describes the fabrication method of an interdigitated array 3D micromesh metal structure for electrochemical sensing electrodes. The inverse-micromesh structure formed by double backside exposure of the thick positive photoresist was utilized as a mold for electroplating. Ring-shaped Au patterns laid open by overexposure of the positive photoresist were employed as a seed layer for electroplating. An electrochemical sensor with interdigitated array 3D micromesh electrodes was realized by using the combination of the double-sided Cr pattern and protecting the resist layer to achieve selective electroplating. The diameter of the inclined micropillars was about 5 νm. The height and length of the micromeshes were 20 νm and 480 νm, respectively. The gap between the micromesh electrodes was 28 νm. The number of micromesh electrodes was 68 (34 anode and 34 cathode electrodes). The performance of the interdigitated array 3D micromesh electrochemical sensor was demonstrated using the redox reaction. The current signal measured by the 3D micromesh electrodes was 7.9 times higher than that of conventional planar electrodes.