John C. Whitehead and Joe N. Lucas
Fluid Driven Reciprocating Apparatus
U.S. Patent 5,616,005
April 1, 1997
A pair of fluid-driven pump assemblies in a back-to-back configuration to yield a bi-directional pump. Each pump assembly includes a piston or diaphragm that divides a chamber into a power section and a pumping section. An intake-exhaust valve connected to each power section functions to direct fluid, such as compressed air, into the power section and to exhaust fluid. At least one of the pistons or diaphragms is connected by a rod assembly, which is constructed to form a signal valve. The intake-exhaust valve of one pump assembly is controlled by the position or location of the piston or diaphragm in the other pump assembly through the operation of the rod assembly signal valve.

Joe N. Lucas, Tore Straume, and Kenneth T. Bogen
Detection and Isolation of Nucleic Acid Sequences Using Competitive Hybridization Probes
U.S. Patent 5,616,465
April 1, 1997
A method in which a target nucleic acid sequence is hybridized to first and second hybridization probes that are complementary to overlapping portions of the target nucleic acid sequence. The first hybridization probe includes a first complexing agent capable of forming a binding pair with a second complexing agent, and the second hybridization probe includes a detectable marker. The first complexing agent attached to the first hybridization probe is contacted with a second complexing agent, which is attached to a solid support such that when the first and second complexing agents are attached, target nucleic acid sequences hybridized to the first hybridization probe become immobilized onto the solid support. The immobilized target nucleic acids are then separated and detected by the identification of the detectable marker attached to the second hybridization probe.

Raymond J. Beach, William J. Benett, and Steven T. Mills
Fiber Optic Coupling of a Microlens Conditioned, Stacked Semiconductor Laser Diode Array
U.S. Patent 5,617,492
April 1, 1997
A system for efficiently coupling the output radiation from a two-dimensional aperture of a semiconductor laser diode array into an optical fiber. The aperture is formed by stacking laser diode bars. Individual microlenses condition the output radiation of the laser diode bars for coupling into the fiber. A simple lens is then used to focus this conditioned radiation into the fiber. The focal length of the lens is chosen such that the divergence of the laser light after it passes through the lens is not greater than the numerical aperture of the optical fiber. The lens must focus the laser light to a spot size that is less than or equal to the input aperture of the optical fiber.

John F. Holzrichter and Wigbert J. Siekhaus
Method for Identifying Biochemical and Chemical Reactions and Micromechanical Processes Using Nanomechanical and Electronic Signal Identification
U.S. Patent 5,620,854
April 15, 1997
A method of operating a scanning probe microscope, such as an atomic force microscope (AFM) or a scanning tunneling microscope (STM), in a stationary mode on a site where an activity of interest occurs to measure and identify characteristic time-varying micromotions caused by biological, chemical, mechanical, electrical, optical, or physical processes. The tip and cantilever assembly of an AFM is used as a micromechanical detector of characteristic micromotions transmitted either directly by a site of interest or indirectly through the surrounding medium. Alternatively, the exponential dependence of the tunneling current on the size of the gap in an STM is used to detect micromechanical movement.

Charles E. Hamilton and Laurence H. Furu
Tunable, Diode Side-Pumped Er:YAG Laser
U.S. Patent 5,623,510
April 22, 1997
A discrete-element Er:YAG (erbium-doped yttrium-aluminum-garnet) laser side-pumped by a laser diode array which generates a tunable output around 2.94 micrometers. The oscillator is a plano-concave resonator consisting of a concave high reflector, a flat output coupler, an Er:YAG crystal, and an intracavity etalon tuning element. The oscillator uses total internal reflection in the Er:YAG crystal to allow efficient coupling of the diode emission into the resonating modes of the oscillator. The laser is useful for tuning to an atmospheric window, as a spectroscopic tool, for medical applications, and for industrial effluent monitoring.

Back to September 1997