Abstract: A beam (38) of electromagnetic radiation deflected by a moving mirror plate (56) of a micromachined scanner (54) produces a two dimensional ("2D") raster (132) on a scanned surface (28) of a block (34). The block (34) is transparent to electro-magnetic radiation of pre-established wavelengths. A radiation inlet-face (36) of the block (34) admits the beam (38) that then impinges on the scanned surface (28) to exit the block (34) through a radiation outlet-face (42). After exiting the block (34), the beam (38) impinges upon a radiation detector (142). Total internal reflection ("TIR") of the beam (38) from the scanned surface (28) at fingerprint valleys and frustration of TIR at fingerprint ridges causes the radiation detector (142) to produce a time-varying electrical signal that represents the fingerprint. The scanned surface (28) may be formed by a patch (302) of resilient material, that may be tinted to be transparent only at the pre-established wavelength of the electro-magnetic radiation.

Abstract: A document transport for a scanner (100) has a flexible, elongated finger (226) disposed adjacent to a document (134), and a force applied to the finger (226) urges teeth (233) on the finger (226) into contact with the document (134) which urges the document (134) along a path through the scanner (100). A piezoelectric plate (222), which applies the force to the finger (226), requires only a small amount of electrical power. To traverse the scanner (100), a document (134) may also be manually fed along a guide (272). First and second speed-sensing detectors (276a and 276b), disposed along the path traversed by the document (134), permit the scanner (100) to determine a speed at which the manually fed document (134) traverses the scanner (100). To conserve electrical energy, the scanner (100) also includes a document-presence detector (274) for activating the scanner (100) when a document (134) to be scanned is present.

Abstract: Two torsion bars project from a reference member to support at least one plate or frame-shaped first dynamic member for rotation about an axis of the torsion bars. In one embodiment, a frame-shaped first dynamic member and a second pair of torsion bars, oriented non-parallel to the first torsion bars, support a second dynamic member for rotation about an axis that is collinear with the second pair of torsion bars. The vibrational frequency of the principal torsional vibrational mode of the dynamic members are respectively lower by at least 20% than the vibrational frequency of any other vibrational mode thereof. Either an electrostatic or electromagnetic drive means imparts rotary motion to the dynamic members about the collinear torsion bar axis(es). The reference member, the torsion bars and the dynamic member(s) are all monolithically fabricated from a stress-free semiconductor layer of a silicon substrate.

Abstract: An improved micromachined structure used for beam scanners, gyroscopes, etc. includes a reference member from which project a first pair of axially aligned torsion bars. A first dynamic member, coupled to and supported from the reference member by the torsion bars, oscillates in one-dimension about the torsion bar's axis. A second dynamic member may be supported from the first dynamic member by a second pair of axially aligned torsion bars for two-dimensional oscillation. The dynamic members respectively exhibit a plurality of vibrational modes each having a frequency and a Q. The improvement includes means for altering a characteristic of the dynamic member's frequency and Q. Coupling between dynamic members permits altering the second dynamic member's frequency and Q by techniques applied to the first dynamic member. Some techniques disclosed also increase oscillation amplitude or reduce driving voltage, and also increase mechanical ruggedness of the structure.

Abstract: A housing for a (silicon) micromachined body (for instance an injector valve system, a detector or a stream selector for a gas chromatograph instrument) is field assemblable and disassemblable and mechanically self-aligning so that the micromachined body may be replaced in the field without tools and without adhesives or permanent bonding. The housing includes a top plate and a bottom plate spaced apart by two side rails and accommodating the micromachined body. The various tubes carrying fluids and pneumatic pressure to and from the micromachined body are attached to the housing by adhesives or brazing or by detachable screw-type fittings. The housing is held in alignment by alignment pins passing through it and is clamped together by a spring clamp which also clamps the housing to a printed circuit board and associated planar heater element. In addition to easy field assembly, this assembly allows manufacturing without precision alignment tools, adhesives, or welding.

Abstract: A micromachined, monolithic silicon flow meter includes a vane 28 from which projects a hinge. The hinge is provided by torsion bars 24. The hinge supports the vane 28 for rotation about the torsion bars 24. A deflection sensor, consisting of a torsion sensor 42, incorporated into at least one of the torsion bars 24, senses deflection of the vane 28 responsive to fluid impinging thereupon. The frame 22, the torsion bars 24, the vane 28 and the torsion sensor 42 are all monolithically fabricated in a semi-conductor single-crystal silicon layer of a substrate.

Abstract: A topographic head for profilometry and AFM supports a central paddle by coaxial torsion bars projecting inward from an outer frame. A tip projects from the paddle distal from the bars. The torsion bars include an integrated paddle rotation sensor. A XY stage may carry the topographic head for X and Y axis translation. The XYZ stage's fixed outer base is coupled to an X-axis stage via a plurality of flexures. The X-axis stage is coupled to a Y-axis stage also via a plurality of flexures. One of each set of flexures includes a shear stress sensor. A Z-axis stage may also be included to provide an integrated XYZ scanning stage. The topographic head's frame, bars and paddle, and the XYZ stage's stage-base, X-axis, Y-axis and Z-axis stages, and flexures are respectively monolithically fabricated by micromachining from a semiconductor wafer.

Abstract: An elongated micromachined silicon hinge includes an integral four-terminal piezo voltage torsion sensor. The micromachined hinge is disposed between masses that are located at opposite ends of the hinge, and that are fabricated integrally with the hinge by micromachining. Concurrent application of a torsional force to the hinge, by rotation of the masses about the hinge's longitudinal axis, and an electric current through the hinge's silicon, generates a voltage that appears across a pair of voltage sensing electrodes.

Abstract: A frequency-locked torsional scanner of the type having a micromachined mirror formed on a surface of a silicon wafer section supported within a larger wafer section by a pair of opposed torsion bars. The principal vibrational frequency of the mirror is selected to be at least 20% higher than other modes of vibration. To prevent breakage, the torsion bars are hardened by conversion of at least a surface layer to silicon carbide or nitride. A pair of scanners with orthogonal torsion bars may be mounted in a vacuum enclosure for two-dimensional scanning at different rates suitable for television display. In alternate embodiments, a detector and a scanner may be built on a plate on the same supported wafer section or two scanners may be independently supported or one scanner and one detector may be independently supported as two plates. The mirror may be driven electrostatically, magnetically, or by both methods.

Abstract: A monolithic single crystal Si rate-gyro consisting of in the preferred embodiment, an outer torsional frame, self resonating with a substantial amplitude, as controlled by a four-terminal piezo torsion sensor, connected to an inner frame by torsional hinges. The inner frame itself is connected to a fixed inner post, by a set of torsion hinges, defining an axis of rotation perpendicular to the first axis. Rotation of the axis of oscillation of the outer body causes the moving mass and the inner frame to tilt and oscillate at the outer frequency due to Coriolis forces, thereby periodically deforming the inner hinges in torsion. These inner hinges are likewise equipped with a four-terminal piezo voltage torsion sensor, giving an indication of the rate of rotation of the sensor. The design allows for good sensitivity, due to the substantial swing of the outer oscillator, its high moment of inertia, excellent Si spring characteristics, and excellent sensitivity of the torsional sensors.

Abstract: A cantilever for a scanning probe microscope is disclosed. The cantilever includes a piezoresistor for detecting the deflection of the cantilever, and a tip which is formed integrally with the cantilever. A process of fabricating such a cantilever is also disclosed, the process yielding a tip which has a high aspect ratio and a small radius of curvature at its apex. A combined atomic force/lateral force microscope including two or more piezoresistors responsive to both the bending and torsion of the cantilever is also disclosed.

Abstract: Forming micro-probe tips for an atomic force microscope, a scanning tunneling microscope, a beam electron emission microscope, or for field emission, by first thinning a tip of a first material, such as silicon. The tips are then reacted with a second material, such as atoms from an organic or ammonia vapor, at a temperature of about 1000.degree. C..+-.200.degree. C. and vacuum conditions for several minutes. Vapors such as methane, propane or acetylene will be converted to SiC or WC while ammonia will be converted to Si.sub.3 N.sub.4. The converted material will have different physical, chemical and electrical properties. For example, a SiC tip will be superhard, approaching diamond in hardness. Electrically conductive tips are suitable for field emission.