A CMOS-based architecture for a distributed sensor matrix in underwater environment

This paper describes a wired addressing architecture of distributed sensors for monitoring real-time in-situ pressure variations in underwater environment. Limits of isolated sensors and drawbacks of acoustic communication are overcome, and an application to the inspection of a submerged structure is made feasible. The prototype sensor is a Kapton/sup /spl reg// based three-layered structure. We fabricated a 0.18 /spl mu/m CMOS mixed-mode system on chip (SoC) as a prototype and a 5-pad chip on board (COB) for unobtrusive monitoring. Testing sessions in the aquatic environment have been carried out, and the dependence of the capacitance from pressure variation is shown when a linear pression variation is exerted. An experimental result in a turbulent operating condition is reported too.