Abstract: A planar micro-motor has a stator supported by a substrate and comprising a planar array of radially extending circumferentially spaced bifilar micro-coils. The micro-motor also has a rotor comprising a rotor body supporting a plurality of elongate, radially extending members or regions circumferentially spaced in a second plane parallel to the plane of the bifilar micro-coils. The radial members are magnetic or otherwise responsive to electromagnetic fields generated by the stator to rotate the rotor. Energizing means selectively energizes subsets of the bifilar micro-coils to generate the electromagnetic fields acting on the magnetic regions of the rotor such that the amount and direction of rotation of the rotor can be controlled. The planar micro-motor can be employed as a gearless stepper motor and can be fabricated using generally known microfabrication techniques.

Abstract: An analog-display device, such as a gauge or the like, includes a moveable display member driven by a planar micro-motor. The micro-motor comprises a substrate, a stator for receiving electrical current to generate an electromagnetic field, and a rotor which is rotatable in response to electromagnetic fields generated by the stator. In the stator, a plurality of electrically conductive micro-coils are supported by the substrate and arrayed in a first plane. A plurality of magnetic members is arrayed in the rotor in a second plane substantially parallel to the first plane. The visible display member of the analog display device is mounted for movement by rotation of the rotor body. Analog display devices of the invention can be used in motor vehicle instrument panels, wherein the micro-motor carrying the display member can be mounted, as by cementing, to the display face of the device.

Abstract: A planar micro-motor and method of fabricating it are disclosed. The planar micro-motor comprises a stator supported by the substrate and preferably comprising a plurality of circumferentially spaced micro-coils lying in a first plane. The micro-motor also has rotor comprising a plurality of magnetic regions circumferentially spaced about a shaft for rotation in a second plane parallel to, and spaced from, the first plane. Actuating elements selectively energize subsets of the micro-coils to generate electromagnetic fields acting on the magnetic regions of the rotor across the planar gap sandwiched between the micro-coils and the rotor. The amount and direction of rotation of the rotor can be controlled. The planar micro-motor can be employed as a stepper motor. It can be fabricated using microfabrication techniques.

Abstract: An acoustic or ultrasonic device includes two ultrasonic energy transmission paths having substantially identical transmission characteristics for a neutral condition of the device. One or both of the transmission paths include path altering structure(s) or coating(s) for changing the transmission characteristics of one or both of the paths in response to a physical phenomenon to be sensed or monitored. The paths have input transducers coupled thereto for transmitting ultrasonic energy into the paths. The input transducers are driven by a single oscillator such that the ultrasonic energy waves generated in the two paths are substantially identical to one another. A drive adjusting circuit compensates for any differences between the two paths and/or the ultrasonic waves in the two paths. An output transducer is coupled to the two paths for receiving ultrasonic waves from the paths and generating an output signal which is the result of combining the acoustic or ultrasonic waves from the two paths.

Abstract: An accelerometer fabricated by silicon etching techniques. A first suspended beam is formed having a first conductive portion, the beam being deflectable in response to an acceleration force. A second beam having second and third conductive portions is suspended over the first beam. Phased lock loop circuitry oscillates the second beam at resonance and provides an electrical signal proportional to the acceleration force.

Abstract: An engine control system for operating an internal combustion engine with any mixture of alcohol and gasoline. The control system includes an air/fuel ratio control system providing a desired fuel charge in relation to the alcohol and gasoline content of the fuel which is indicated by an optical sensor. In one embodiment, the optical sensor includes a hemispherical lens having hemispherical recesses formed through the lens base equidistant from the lens plane of symmetry. A light emitting diode positioned in one recess irradiates substantially the entire 2 .pi. steradian outer surface of the hemispherical lens. A portion of the transmitted light is reflected from substantially the entire hemispherical lens and substantially focused on a photodetector positioned in the other recess. Emitter and detector are substantially positioned at conjugate focii of the lens which provides substantially a 2 .pi. steradian collection aperture.

Abstract: An accelerometer fabricated by silicon etching techniques. A first suspended beam is formed having a first conductive portion, the beam being deflectable in response to an acceleration force. a second beam having second and third conductive portions is suspended over the first beam. Phased lock loop circuitry oscillates the second beam at resonance and provides an electrical signal proportional to the acceleration force.

Abstract: A suspended element etched in a silicon substrate whcih is deflected in linear proportion to an applied force. A pair of flexing member symmetrically positioned around the suspended element provides rectilinear movement of the suspended element in response to the applied force. In one embodiment of the invention, the flexing member is formed in a single etchant step by concurrently etching nearly identical recesses into opposing planar surfaces of the silicon substrate. In this embodiment, the portions of silicon remaining between the recesses and planar surfaces define the flexing member.

Abstract: A silicon substrate having {100} nominal crystalline planes is anisotropically etched to form a pair of V-shaped grooves along the top planar surface and a first plate between the grooves. The top planar surface is then doped to form a conductor region including the first plate. A substantially uniform layer of a selectively etchable material, such as silicon oxide, is then grown over the grooved top planar surface. A layer of doped silicon is grown over the silicon oxide layer to define a pair of V-shaped members opposite the pair of grooves. The silicon layer is then partially etched to form a second plate connected to the silicon layer through a pair of V-shaped members. Both the second plate and the pair of V-shaped members are then suspended over the first capacitive plate by sacrificially etching a portion of the selectively etchable layer.

Abstract: A method for anisotropically etching an aperture into a monocrystaline substrate such that the angle of the aperture plane with respect to the nominal crystaline planes of the substrate may be preselected. Etchant pits through opposing planar surfaces are offset from one another by a preselected longitudinal offset trigonometrically related to the desired aperture angle. Other selected parameters trigonometrically related to the aperture plane include: the intersecting angle of the intersecting crystaline planes with the nominal crystaline planes; substrate thickness; and depth of each of the etchant pits.