Abstract: A microaccelerometer is provided for use in on-board automotive safety control and navigational systems. The microaccelerometer includes a central support body which is supported upon a backing chip, a peripheral proof mass which circumscribes the central support body, and at least one pair of microbridges, each of which are attached to both the central support body and the peripheral proof mass. The pair of microbridges extend outwardly in opposite directions from the central support body such that a longitudinal axis through each of the microbridges forms a common axis through the central support body. The microbridges are attached to the peripheral proof mass at the end opposite the central support body so as to suspend the peripheral proof mass circumferentially about the central support body and above the backing chip.

Abstract: A resonant bridge two-axis microaccelerometer is disclosed comprising polysilicon resonant bridges orthogonally attached to a silicon proof mass, such that the silicon proof mass is suspended by the resonant bridges. Acceleration in the plane of the substrate causes differential axial loads on the opposing microbridges in each pair, thereby shifting their resonant frequencies. The acceleration component aligned with a pair is measured by the difference in resonant frequencies.

Abstract: A method of producing a miniaturized, fixed volume, internal reference gas chamber comprising the pores of a porous material, suitable for use in a rapid response, highly precise, internal reference, solid electrolyte electrochemical-type oxygen sensor capable of detecting oxygen partial pressures in internal combustion engines operating within lean air/fuel mixtures is accomplished using a four step technique. A thin film layer of material is deposited onto a supporting substrate and patterned, said material comprises at least one component resistant to a subsequent removal step and at least one sacrificial component not resistant to the same subsequent removal step. The said material is then sealed everywhere except at an external orifice. The sacrificial component of said material is then decomposed and removed during a removal step, providing an interlocking network of porosity comprised within the porous component of said material.

Abstract: A method of producing a miniaturized, fixed volume, internal reference gas chamber comprising the pores of a porous material, suitable for use in a rapid response, highly precise, internal reference, solid electrolyte electrochemical-type oxygen sensor capable of detecting oxygen partial pressures in internal combustion engines operating within lean air/fuel mixtures is accomplished using a four step technique. A thin film layer of material is deposited onto a supporting substrate and patterned, said material comprises at least one component resistant to a subsequent removal step and at least one sacrificial component not resistant to the same subsequent removal step. The said material is then sealed everywhere except at an external orifice. The sacrificial component of said material is then decomposed and removed during a removal step, providing an interlocking network of porosity comprised within the porous component of said material.

Abstract: A method is disclosed for forming a semiconductor tin oxide thin film on a selected region of a surface without forming the film on an adjacent region. An ink film composed of tin(II) carboxylate compound is applied to the surface and heated to partially decompose the compound. A positive photoresist layer is preferably applied to the partially decomposed layer and selectively irradiated to define a mask overlying the selected region. Unwanted photoresist material is dissolved from the adjacent region using an aqueous alkaline solution. It is found that the solution concurrently dissolves the underlying partially decomposed tin compound, without dissolving the compound protected by the mask. Thereafter, the mask is stripped, and the underlying tin compound is heated and further decomposed to produce the desired tin oxide thin film.

Abstract: A preferred semiconductor gas sensor of this invention features a gas interaction site comprising a gas sensitive semiconductor thin film and means for heating the film to an operative temperature. The thin film and heating means are carried upon a region of a substrate that is etched opposite the site to reduce the thickness of the region and thereby reduce heat flow from the region into a surrounding region.