AN ELECTROCHEMICAL MICROFLUIDIC BIOSENSOR PLATFORM FABRICATED BY ADDITIVE MANUFACTURING AND SUPERSONIC CLUSTER BEAM DEPOSITION

Fused Filament Fabrication (FFF) three-dimensional printing have attracted much attention for fabrication of microfluidic platforms used to construct electrochemical microfluidic biosensors because of high process speed, low production costs and the possibility of manufacturing directly from virtual data. Because of poor adhesion between metal electrodes fabricated using conventional techniques and FFF printed thermoplastic substrates, electrodes are usually integrated into the devices either modularly or using adhesive layers placed at the bottom of fluidic channels. These have hindered the exploitation of FFF for scale-up manufacturing of monolithically integrated microfluidic biosensors. In this work, supersonic cluster beam deposition (SCBD) was employed to fabricate strongly anchored nanostructured electrodes integrated into FFF printed microfluidics platforms. SCBD enables the formation of well-adhering metallic thin film electrodes by implanting supersonically accelerated neutral metal clusters into polymeric substrates. The SCBD also enables deposition over large areas using noble metals and metal oxides with precisely controlled geometry and surface topography. A novel integrated manufacturing approach was developed and optimized to couple SCBD fabricated electrodes with consumer-grade FFF printed microfluidics, employing acrylonitrile butadiene styrene as the base material, to develop a three electrodes configuration electrochemical sensor on-a-chip. Electrochemical investigation performed using stagnant ferro/ferricyanide probe showed that the integrated device possesses high sensitivity and functionality as an electrochemical sensor. In addition, in-channel laminar flow electrochemical detection conducted using the same probe showed robust stability in the system response for online dynamic detection. The integrated platform could be employed for various customized clinical, industrial, and environmental sensing applications.