Abstract: Disclosed herein is an analyte sensing device capable of continuously monitoring metabolic levels of a plurality of analytes. The device comprises an external unit, which, for example, could be worn around the wrist like a wristwatch or could be incorporated into a cell phone or PDA device, and an implantable sensor platform that is suitable, for example, for implantation under the skin. The external device and the internal device are in wireless communication. In one embodiment, the external device and the internal device are operationally linked by a feedback system. In one embodiment, the internal device is encapsulated in a biocompatible coating capable of controlling the local tissue environment in order to prevent/minimize inflammation and fibrosis, promote neo-angiogenesis and wound healing and this facilitate device functionality.

Abstract: An optical deflection device for manipulating optical beams employs a set of layers having the configuration NUPUN . . . , where the N and P symbols refer to N-type and P-type dopants and the U symbol refers to an electrooptically active optical guide layer having an index of refraction sufficiently higher than that of the N- and P- layers that light is guided within it and a free electron concentration low enough that the guide layers are depleted, so that light is guided within the layers with low loss, while the N- and P- layers have an appropriate bias applied to establish a differential phase shift between layers to deflect emitted radiation along a desired angle.

Abstract: A semiconductive sensor or transducer (100), for example, a pressure sensor utilizing capacitance variations to sense pressure variations, of the silicon-on-silicon type, in which a "hinge" (111A) in the form of a relatively thin, encircling area is provided at the outer peripheral edge of the diaphragm, causing the central region (117) of the diaphragm (111) to move in a linear, non-curved or planar manner (compare FIG. 2 to FIG. 1), providing a linear response or frequency output. A first embodiment (FIG. 3) of the hinged silicon-on-silicon capacitive pressure sensor, which is basically cylindrical in shape, has the hinge formed by etching, milling or machining away some of the thickness of the diaphragm at its outer peripheral edge. In a second embodiment (FIG.

Abstract: A pressure sensor (210) utilizing capacitance variations to sense pressure variations of the silicon-glass-silicon type (FIG. 3) including a conductive silicon substrate (212), a conductive silicon diaphragm (211) and a glass dielectric layer (213) therebetween forming a spacing wall (216) between them, in which dielectric drift and parasitic (non-pressure sensitive) capacitance is minimized by including a very thin, third, symmetrical, silicon, capacitive plate (220) in the glass wall (216). The third conductive plate encircles the central region (Cc) of the sensor and is located outside of it. Improved assembly techniques, including all symmetrical planar layers, for higher manufacturing yield and better long term reliability are also disclosed.

Abstract: A micromachined three-plate capacitive accelerometer incorporates hinges attached to top and bottom surfaces of the proof mass that are symmetric about X and Y axes and also about diagonal axes; passageways for gas film damping in the fixed members that do not affect the capacitance to any significant degree; and provision for independently selecting two of the parameters sensitivity, capacitance and maximum acceleration.

Abstract: Semiconductor structures for electronic use, such as for example a silicon-glass-silicon pressure sensor (Fig. 3), include mesa or pedestal structures (12A) extending up from silicon substrates (12). In the invention the mesa structures are fabricated in an oxidation process applied in a cyclical fashion (steps 1-3 through 1-5 of Fig. 1). Each cycle includes a photolithographic operation to protect the previously grown oxide on the mesas from etching. During each cycle less oxide is grown (or conversely silicon consumed) on the mesas than in the preceding cycle, while equivalent amounts of oxide are grown on non-mesa areas in each cycle. As a result, the tops of the mesas get higher and higher above the surrounding areas in each cycle. In order to prevent the leaving of any oxide "scraps" in a non-mesa area during the oxidation steps, resulting from a flaw in the mask, a double exposure process is used, utilizing two completely independent masks, with a positive working photo-resist.

Abstract: A pressure sensor (10) having over-protection for use in environments which subject the sensor to large pressure overloads, such as may occur when such sensor is exposed to jet and automobile engine backfires, explosive gas furnace ignitions and similar high pressure events. Essentially two capacitive sensors are bonded together, diaphragm-to-diaphragm, with the diaphragms (111A/111B) spaced but juxtaposed and forming a closed, reference cavity chamber (114) between them, along with a central, side, wall spacer (116C). The capacitance variation with differential pressure is measured between the two diaphrams and with reference to their respective bases (112A/112B). Each of the diaphragms preferably is provided with a center bearing or stops (115A/115B) for accepting the load when over-pressured. When in contact at the center, the stiffness of the combined pair of diaphragms is increased several fold over that of a single diaphragm.

Abstract: A capacitive pressure transducer has a pedestal 25 formed in a silicon layer 14 surrounded by a moat 26 extending through the silicon layer, with borosilicate glass 17, 22 at the edges of the silicon layer forming the walls of the pressure chamber, with a wafer 28 of silicon bonded thereto. The pedestal 25 is joined to the walls of the vacuum chamber by borosilicate glass 16, whereby it is wholly, electrically isolated therefrom. A method of forming a capacitive pressure transducer utilizing the variable etch rates of aluminum, glass and silicon, together with field assisted bonding, is also disclosed.

Abstract: Low cost, easily reproducible piezoelectric deflector (8) operable with low voltages is achieved by providing an interdigital electrode configuration (12, 13) on a surface of piezoelectric material (10) having alternate sites (15, 16) with different piezoelectric response. A preferred embodiment polarizes the sites oppositely in a piezoelectric ceramic substrate (10). Alternate sites in piezoelectric crystals may be removed or have their piezoelectricity substantially reduced. Differential devices (8a, 8b) employ electrodes on both surfaces of the substrate, with a site at one surface being poled oppositely to an adjacent site at the other surface (FIG. 3) or with adjacent sites at both surfaces poled alike, and signal voltages applied oppositely (FIG. 4).

Abstract: A three plate silicon-glass-silicon capacitive pressure transducer includes a conductive silicon diaphragm and substrate relatively spaced by a dielectric body having disposed therein a central electrode positioned between the diaphragm and substrate to form a pressure responsive capacitance with the diaphragm at a value inversely proportional to a pressure signal applied to a pressure sensing surface of the diaphragm.

Abstract: A plurality of silicon pressure transducers 10 are formed by processing two conductive silicon wafers 11, 14, one of the wafers including a layer of borosilicate glass 32, a thin portion of which 17 is on the surface 12 of one of the plates of a capacitor formed by field-assisted bonding together of the two wafers, the thin layer of borosilicate glass avoiding arcing during the field-assisted bonding process.

Abstract: A silicon capacitive pressure transducer 34 comprising two wafers of silicon 14, 32 separated by borosilicate glass 18, 21, one of the wafers 14 having a borosilicate glass pedestal 26 thereon which is metallized 30 to provide one plate of a capacitor, the other plate of which is the surface of one of the silicon wafers 32. The distance between the upper surface of the glass pedestal and the lower surface of the silicon wafer is defined by a portion 18 of the borosilicate glass, the portion 21 of borosilicate glass being the same height as that of the glass pedestal 26. An embodiment of a transducer 34b employs a silicon pedestal 26b, wherein the glass portion 21b only provides separation of the silicon wafers 14b, 32b with lower parasitic capacitance.

Abstract: A method is provided for pattern masking objects preparatory to subsequent working of the objects. The invention also includes those objects prepared in accordance with the method. The method is especially suited to the pattern-masking of relatively large and/or complexly shaped optical elements preparatory to the production of diffraction gratings thereat for use with laser radiation.The object to be worked, such as a mirror, is coated with a semiconductive masking material. Electrolytic etchant is placed on the masking material. Electromagnetic radiation of suitable wavelength and patterned in accordance with the desired pattern of the mask is projected through the etchant and onto the masking material. The radiation effects photoelectrochemical etching of the semiconductive masking material in the desired pattern to a desired depth. An etch-stop layer may be interposed between the object and the masking material to limit the etching action.

Abstract: Radiant energy in conjunction with an n-type amorphous silicon semiconducting photoanode to at least partially power an electrolytic cell is used in the generation of hydrogen, utilizing a bromide, preferably hydrogen bromide, as the essential electrolyte component in the electrolytic cell to solve overvoltage and corrosion problems associated with the use of conventional electrolytes in similar environments. The use of the bromide electrolyte results in the broadening of the selection of semiconductor electrodes which can be used in the process and apparatus of the present invention enabling the amorphous silicon semiconducting electrode to be used with superior anticorrosive and radiant energy gathering results over conventional systems. To insure against corrosion, the amorphous silicon semiconductor should preferably be used with a thin layer of platinum overcoating. The hydrogen generated from such system can be used to power a fuel cell.

Abstract: Radiant energy in conjunction with a boron phosphide semiconducting electrode to at least partially power an electrolytic cell is used in the generation of hydrogen, utilizing a bromide, preferably hydrogen bromide, as the essential electrolyte component in the electrolytic cell to solve overvoltage and corrosion problems associated with the use of conventional electrolytes in similar environments. The use of the bromide electrolyte results in the broadening of the selection of semiconductor electrodes which can be used in the process and apparatus of the present invention enabling the boron phosphide semiconducting electrode to be used with superior anticorrosive and radiant energy gathering results over conventional systems. The boron phosphide semiconductors employed can be either boron phosphide alone or multilayered structures with other semiconducting material. The hydrogen generated from such systems can be used to power a fuel cell.

Abstract: Method and apparatus are disclosed for producing oxygen and hydrogen bromide in an electrolytic cell utilizing, as the cathode, a consumable bromine electrode comprising bromide ions dissolved in a pool of liquid bromine surrounding a metal electrode. The electrolytic cell also contains a water solution of an electrolyte on both sides of a hydrogen ion permeable membrane forming a two-compartment electrolytic cell. In operation of the preferred process, hydrogen bromide gas is given off in the cathode compartment and oxygen gas is given off in the anode compartment.

Abstract: Method and apparatus are disclosed for producing oxygen and hydrogen bromide in an electrolytic cell utilizing, as the cathode, a consumable bromine electrode comprising bromide ions dissolved in a pool of liquid bromine surrounding a metal electrode. The electrolytic cell also contains a water solution of an electrolyte on both sides of a hydrogen ion permeable membrane forming a two-compartment electrolytic cell. In operation of the preferred process, hydrogen bromide gas is given off in the cathode compartment and oxygen gas is given off in the anode compartment.

Abstract: Radiant energy to at least partially power an electrolytic cell is used in the generation of hydrogen, utilizing a bromide, preferably hydrogen bromide, as the essential electrolyte component in the electrolytic cell to solve overvoltage and corrosion problems associated with the use of conventional electrolytes in similar environments. The use of such material also results in a broadening of the selection of semiconductor electrodes which can be used in such process and apparatus. The semiconductors employed are generally nonmetals and can be multilayered structures comprised of a gradient of diminishing width band gap material. The hydrogen generated from such system can be used to power a fuel cell.