Abstract: A combinatorial microenvironment generator is configured for the generation of arbitrary, user-defined, steady-state, concentration gradients with negligible to no flow through the growth medium to perturb diffusion gradients or cellular growth. More importantly, the absolute concentrations and/or gradients can be dynamically altered upon request both spatially and temporally to impose tailored concentration fields for in-situ stimulus studies. Here, diffusion occurs via an array of ports, each of which can be an independently controlled source/sink. Together, the array of ports establishes a user-defined, 3D concentration profile. Useful methods related to this device are also provided.

Abstract: A combinatorial microenvironment generator is configured for the generation of arbitrary, user-defined, steady-state, concentration gradients with negligible to no flow through the growth medium to perturb diffusion gradients or cellular growth. More importantly, the absolute concentrations and/or gradients can be dynamically altered upon request both spatially and temporally to impose tailored concentration fields for in-situ stimulus studies. Here, diffusion occurs via an array of ports, each of which can be an independently controlled source/sink. Together, the array of ports establishes a user-defined, 3D concentration profile. Useful methods related to this device are also provided.

Abstract: A method and apparatus for puncturing a surface for extraction, in situ monitoring, and/or substance delivery uses microneedles with improved properties. Applications include easy to handle glucose monitoring using a group of hollow out-of-plane silicon microneedles to sample substances in interstitial fluid from the epidermal skin layer.

Abstract: Micro-electro-mechanical (MEM) translational tabs are introduced for enhancing and controlling aerodynamic loading of lifting surfaces. These microtabs are mounted at or near the trailing edge of lifting surfaces, deploy approximately normal to the surface, and have a maximum deployment height on the order of the boundary layer thickness. Deployment of this type of device effectively changes the camber, thereby affecting the lift generated by the surface. The effect of these microtabs on lift is as powerful as conventional control surfaces such as ailerons. Application of this simple yet innovative lift enhancement and control device will permit the elimination of some of the bulky conventional high-lift and control systems and result in an overall reduction in system weight, complexity and cost.

Abstract: Micro-electro-mechanical (MEM) translational tabs are introduced for enhancing and controlling aerodynamic loading of lifting surfaces. These microtabs are mounted at or near the trailing edge of lifting surfaces, deploy approximately normal to the surface, and have a maximum deployment height on the order of the boundary layer thickness. Deployment of this type of device effectively changes the camber, thereby affecting the lift generated by the surface. The effect of these microtabs on lift is as powerful as conventional control surfaces such as ailerons. Application of this simple yet innovative lift enhancement and control device will permit the elimination of some of the bulky conventional high-lift and control systems and result in an overall reduction in system weight, complexity and cost.

Abstract: A detector cell for a silicon-based or non-silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The detector cell is an electrochemiluminescence cell constructed of layers of silicon with a cover layer of glass, with spaced electrodes located intermediate various layers forming the cell. The cell includes a cavity formed therein and fluid inlets for directing reaction fluid therein. The reaction chamber and detector cell may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The ECL cell may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

Abstract: Low residual stress, stoichiometric or near stoichiometric, silicon nitride and silicon carbide films with thicknesses of one micron or greater are produced by reacting porous silicon with a nitrogen or carbon containing gas, such as ammonia or methane, at an appropriate temperature and pressure. The gas diffuses into the pores and reacts with the silicon skeletal structure. Because the initial structure is porous and the pore spaces provide strain relief during the addition reaction and subsequent volume expansion, the resultant film has relatively low residual stress. Either porous or solid films can be produced. This process provides a means to chemically stabilize porous silicon layers and their morphologies.

Abstract: An interferometric-based pressure transducer is fabricated from two layers of silicon having different crystal orientations which have been processed using selective anisotropic etching to produce in one silicon layer a mirror surface and a groove that is aligned with the mirror, and a pressure-responsive membrane in the other layer. The layers are joined with the membrane opposite the mirror, and an optical fiber is secured in the groove so that light from the optical fiber is conveyed by the mirror surface between the membrane and the optical fiber. Conventional interferometric apparatus compares transmitted and received light in order to sense deformation of the membrane and thereby sense pressure.

Abstract: Electrochemical microsensors formed of a substrate containing means for sensing potential or current, including active and passive electronic devices and electronic circuits, and a micromachined structure containing at least one cavity overlying the sensing means, wherein the structure and substrate are bonded together at a temperature less than about 400.degree. C., in the absence of high voltage fields, using means not requiring highly planarized surfaces. A wide variety of materials can be utilized for both the substrate and overlying structure.Diverse embodiments are possible, having in common a cavity containing a chemically sensitive material and means for sensing potential or current.The resulting structural organization of materials transduces a chemical signal, such as concentration, to an electrical signal, which is then "processed" by the underlying FET or metallic connections.

Abstract: This invention relates to a miniature reference electrode of the liquid junction-type which is utilized by an integrated electrochemical sensor, which functions as an Ion Sensitive Field Effect Transistor.

Abstract: A solid state chemically sensitive integrated circuit includes three field-effect transistors (FETs) fabricated on a single semiconductor substrate. The gate of a first FET is overlaid with a chemically sensitive element that is adapted to create an electrochemical potential at the gate when exposed to selected chemical substances. This gate is also electrically connected to the source of a second FET and the drain of a third FET. The second and third FETs are used as switches to selectively connect the gate of the first FET to ground, to an external reference potential, or to isolate it from all external signals. In the latter case, only the interaction between the chemically sensitive element and external chemical substances may affect the first FET's operation thus allowing the first FET, when so isolated, to provide a measure of the chemical properties of the substance to which its chemically sensitive element is exposed.