Patent ID: 7694552

Claim:
A sensor subassembly for use in fluid immersion applications, the sensor subassembly comprising: one or more membranes, each said membrane having a sensor surface and a back surface facing away from said sensor surface, wherein each said sensor surface is in contact with a fluid during operation of said sensor subassembly, and wherein each said back surface is not in contact with said fluid during operation of said sensor subassembly; a frame around said one or more membranes and attached to perimeters of said one or more membranes, whereby each of said one or more membranes can act as a mechanical resonator during operation of said sensor subassembly; one or more pressure-release boundary regions, disposed on said frame in proximity to said one or more membranes and in contact with said fluid during operation of said sensor subassembly; wherein said pressure-release boundary regions have a smaller mechanical impedance than said fluid at interfaces between said pressure-release boundary regions and said fluid.