Abstract: Capacitor technology that provides a high density, high reliability capacitor that is capable of operating at high temperature, for example for use in downhole tools. The capacitive cells have an insulating dielectric of crystalline diamond deposited on a substrate of silicon. Methods of manufacturing capacitor cells are also disclosed, as are stacked configurations of single die capacitors.

Abstract: A sensor for measuring a parameter of a fluid includes a housing defining a fluid-proof chamber and an area of reduced thickness defining a membrane separating the chamber from the fluid. An actuating/detecting element is positioned within the chamber and mechanically coupled with the membrane. The actuating/detecting element includes a multilayer structure, having a metallic material member having a first metallized layer, and a piezoelectric material member having a second metallized layer connected to the first metallized layer via a sintered silver joint. A resonating element is mechanically coupled with the membrane and extends from the membrane, the resonating element being sized and dimensioned to transfer mechanical vibrations to and from the actuating/detecting element.