An integrated fluidic electrochemical sensor manufactured using fused filament fabrication and supersonic cluster beam deposition

We present a fluidic electrochemical sensor fabricated with an additive manufacturing approach based on the combination of fused filament fabrication (FFF), supersonic cluster beam deposition (SCBD) and selective electroplating. The system consists of a miniaturized three electrode electrochemical detection unit integrated into a polymer-based monolithic fluidic platform. SCBD is used to directly print functional working and counter gold electrodes with a large surface area and low electrical resistance onto the bottom surface of a fluidic channel, manufactured by means of consumer-grade FFF. SCBD is also employed to pattern a conductive gold line into the channel, over which an Ag/AgCl quasi-reference electrode is then selectively electroplated. An optimized overprinting procedure is then implemented to seal the channel, guaranteeing the packaging of the system. The fluidic sensor was tested with standard electrochemistry techniques by using the redox couple potassium ferricyanide/potassium ferrocyanide as a probe, both in static and dynamic flow conditions. The sensor showed a reproducible electrochemical behavior, high sensitivity, and a convection rate-dependent response. The proposed manufacturing strategy has potential for the production of integrated fluidic devices for online electrochemical detection and analysis for bio-sensing applications.