摘要:
The present invention includes several nanotube structures which can be made using catalyst islands disposed on a substrate (e.g. silicon, alumina, or quartz) or on the free end of an atomic force microscope cantilever. The catalyst islands are capable of catalyzing the growth of carbon nanotubes from carbon containing gases (e.g. methane). The present invention includes an island of catalyst material (such as Fe2O3) disposed on the substrate with a carbon nanotube extending from the island. Also included in the present invention is a pair of islands with a nanotube extending between the islands, electrically connecting them. Conductive metal lines connected to the islands (which may be a few microns on a side) allows for external circuitry to connect to the nanotube. Such a structure can be used in many different electronic and microelectromechanical devices. For example, a nanotube connected between two islands can function as a resonator if the substrate beneath the nanotube is etched away. Also, the present invention includes a catalyst particle disposed on the free end of an AFM cantilever and having a nanotube extending from the particle. The nanotube can be used as the scanning tip of the AFM as is know in the art.
摘要:
A scanning probe microscope is used to pattern a layer of resist, and the pattern is transferred to a substrate. First, an underlayer formed of, for example, polyimide and a top layer formed of, for example, amorphous silicon are deposited on the substrate. A pattern is formed on the top layer using the tip of the cantilever in a scanning probe microscope. The pattern may consist of an oxide formed by an electric field at the cantilever tip. The top layer is then etched using the pattern as a mask and using an etchant that is selective against the underlayer. The underlayer is then etched using an etchant that is selective against the top layer and substrate. The substrate is etched with an etchant that removes the top layer but is selective against the underlayer. Finally, the underlayer is removed.
摘要:
A scanning probe microscope is used to fabricate a gate or other feature of a transistor by scanning a silicon substrate in which the transistor is to be formed. An electric field is created between the cantilever tip and the silicon substrate, thereby causing an oxide layer to be formed on the surface of the substrate. As the tip is scanned across the substrate the electric field is switched on and off so that an oxide pattern is formed on the silicon. Preferably, the oxide pattern is formed on a deposited layer of amorphous silicon. Extremely small features, e.g., a MOSFET gate having a length of 0.2 .mu.m or less can be fabricated by this technique.
摘要:
The invention provides a method of screening a library of candidate agents by contacting the library with a target in a reaction mixture under a condition of high stringency, wherein the target includes a tag that responds to a controllable force applied to the tag, and passing the members of the library through a microfluidic device in a manner that exposes the library members to the controllable force, thereby displacing members of the library that are bound to the target relative to their unbound counterparts. Kits and systems for use with the methods of the invention are also provided.
摘要:
A microfluidic device may employ one or more sorting stations for separating target species from other species in a sample. The separation is driven by magnetophoresis. A sorting station generally includes separate buffer and sample streams. A magnetic field gradient applied to the sorting station deflects the flow path of magnetic particles (which selectively label the target species) from a sample stream into a buffer stream. The buffer stream leaving the sorting station is used to detect or further process purified target species labeled with the magnetic particles.
摘要:
A microfluidic device may employ one or more sorting stations for separating target species from other species in a sample. The separation is driven by magnetophoresis. A sorting station generally includes separate buffer and sample streams. A magnetic field gradient applied to the sorting station deflects the flow path of magnetic particles (which selectively label the target species) from a sample stream into a buffer stream. The buffer stream leaving the sorting station is used to detect or further process purified target species labeled with the magnetic particles.
摘要:
Screening in a microfluidic device is mediated by a magnetic field that in some manner displaces or otherwise activates the entities of interest. Entities of interest can be identified and/or separated from one or more other components provided to the microfluidic device. Microfluidic devices may have mechanisms that apply a defined magnetic field to a region of the microfluidic device where library members pass through sequentially and/or in parallel.
摘要:
The invention provides a method of screening a library of candidate agents by contacting the library with a target in a reaction mixture under a condition of high stringency, wherein the target includes a tag that responds to a controllable force applied to the tag, and passing the members of the library through a microfluidic device in a manner that exposes the library members to the controllable force, thereby displacing members of the library that are bound to the target relative to their unbound counterparts. Kits and systems for use with the methods of the invention are also provided.
摘要:
A MEMs device comprises a component layer including a frame structure and at least one component movably coupled to the frame and an actuator layer including at least one conductive path and at least one actuator for moving the component. The component layer and the actuator layer are bonded together with solder or other materials in lateral alignment. Advantageously the layers are provided with metallization pads and are bonded together in lateral alignment with predetermined vertical gap spacing by solder bonds between the pads. In a preferred embodiment the MEMs device, however bonded, comprises a component layer, an actuator layer and an intervening spacer. The spacer provides the walls of a cavity between the component and the pertinent actuators to permit movement of the component. The walls cover the bulk of the peripheral boundary of the cavity to provide aerodynamic isolation. Advantageously the walls are conductive to provide electrostatic isolation. The device has particular utility in optical cross connection, variable attenuation and power gain equalization.
摘要:
Provided are novel single-stranded oligonucleotide probes that have a triple-stem configuration in the absence of target binding to the target binding sequence. The probes also have a fluorophore and a quencher. In the absence of target binding to the target binding sequence, these single-stranded oligonucleotide probes are capable of forming self-complementary duplexes such that the probe is in the triple-stem configuration and the fluorophore is positioned adjacent the quencher. In the presence of target binding to the target binding sequence, formation of the self-complementary duplexes is inhibited such that the probe is configured to position the fluorophore away from the quencher such that a signal of the fluorophore is detectable. Also provided are methods of using the probes.