A charge based sigma delta capacitive sensor for ultrathin polyelectrolyte layer detection

In this paper, we present a hybrid microfluidic/CMOS sensor for lab-on-chip (LoC) applications. This hybrid device features a sigma delta (SigmaDelta) capacitive sensor implemented through 0.18 mum CMOS process, a direct-write microfluidic channel and ultrathin polyelectrolyte layers (PLs). We demonstrate the simulation and experimental results and show the viability of the proposed sensor for molecular detection purposes using chitosan and alginate solutions.