A system of parallel and selective microchannels for biosensor sample delivery and containment

This paper presents an integrated microfluidic system for selectively interrogating parallel biosensors at programmed time intervals. Specifically, the microfluidic system is used for delivering a volume of sample from a single source to a surface-based arrayed biosensor. In this case the biosensors were an array of electrochemical electrodes modified with sample specific capture probes. In addition, the sample was required to be captured, stored and removed for additional laboratory analysis. This was accomplished by a plastic laminate stack in which each thin laminate was patterned by CO₂ laser ablation to form microchannels and two novel valves. The first valve was a normally closed type opened by heat via an electrically resistive wire. The second valve was a check type integrated into a removable storage chamber. This setup allows for remote and leave-behind sensing applications and also containment of sensed sample for further laboratory analysis.