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Microfabricated DNA analysis system. Semi-annual report, August 1993--January 1994

Description: We are miniaturizing instrumentation for the polymerase chain reaction (PCR) -- a bioanalytical technique that amplifies target sections of DNA through thermal cycling. This report focuses on delineating reaction chamber, design parameters through computer modeling and infrared imaging. We have also continued micro-chamber-based PCR experiments and have successfully amplified three different targets from two different biological sources. Specifically, we have amplified DNA from {beta}-globin (a subunit of hemoglobin), and two different-sized targets from the Human Immunodeficiency Virus (HIV). These experiments were performed in newly-designed chambers. Reaction chambers are also being designed with detection in mind, specifically for the detection of fluorescent DNA labels. Finally, some new developments in PCR technology are described as they represent potential biological diagnostics to be evaluated in microfabricated DNA analysis systems.
Date: January 1, 1994
Creator: Northrup, M. A.
Partner: UNT Libraries Government Documents Department

Thin film conductive polymer for microactuator and micromuscle applications

Description: Conductive polymer/polyimide bimorphic microcantilevers have been actuated vertically (out-of-plane) upon the volumetric changes induced by electrochemical doping of the polymer. The microcantilevers that are 200-500 {mu}m in length and 50-100 {mu}m in width can be fully extended from a circularly-curled geometry, and thus generate more than 100 {mu}m displacement. Dynamically the microcantilevers have been driven as fast as 1.2 Hz and the polymer was stable for over a week stored in air and light. Residual stresses in the polymer film is estimated to be as high as 254 MPa, and actuation stresses are as high as 50 MPa.
Date: April 14, 1994
Creator: Lee, A.P.; Hong, K.; Trevino, J. & Northrup, M.A.
Partner: UNT Libraries Government Documents Department

A MEMS-based miniature DNA analysis system

Description: We detail the design and development of a miniature thermal cycling instrument for performing the polymerase chain reaction (PCR) that uses microfabricated, silicon-based reaction chambers. The MEMS-based, battery-operated instrument shows significant improvements over commercial thermal cycling instrumentation. Several different biological systems have been amplified and verified with the miniature PCR instrument including the Human Immunodeficiency Virus; both cloned and genomic DNA templates of {beta} globin; and the genetic disease, Cystic Fibrosis from human DNA. The miniaturization of a PCR thermal cycler is the initial module of a fully-integrated portable, low-power, rapid, and highly efficient bioanalytical instrument.
Date: April 25, 1995
Creator: Northrup, M.A.; Gonzalez, C. & Hadley, D.
Partner: UNT Libraries Government Documents Department

Mixed-sputter deposition of Ni-Ti-Cu shape memory films

Description: Ni-Ti-Cu shape memory films were mixed-sputter deposited from separate nickel, titanium, and copper targets, providing increased compositional flexibility. Shape memory characteristics, examined for films with 7 at. % Cu and 41--51 at. % Tl, were determined with temperature controlled substrate curvature measurements, and microstructure was studied with transmission electron microscopy. The Ni-Ti-Cu films were found to have shape memory properties comparable to bulk materials, with transformation temperatures between 20 and 62{degree}C, a 10--13{degree}C hysteresis, and up to 330 MPa recoverable stress.
Date: May 1, 1994
Creator: Krulevitch, P.; Ramsey, P. B.; Makowiecki, D. M.; Lee, A. P.; Northrup, M. A. & Johnson, G. C.
Partner: UNT Libraries Government Documents Department