mechanical and fluid systems
Wafer Level Microchannel Fabrication Process for Lab-on-a-Chip Devices
The microchannel chip is created from a silicon bottom wafer and Pyrex top wafer anodically bonded. Specialized microbeads with specific structure and surface chemistry are placed along the channels. Different species of analyte molecules will interact more strongly with the column chemistry and will therefore take longer to traverse the column, i.e., have a longer retention time. In this way, the channels separate molecular species based on their chemistry. The specific shape and surface chemistry of these microchannels do more than just move analyte moleculesthe molecules are separated by how they are affected by the channels chemistry for expedited analysis. Paired with mass spectroscopy or ChemFET technology, this technology could enhance research and development in microchemistry, microfluidics, and lab-on-a-chip technology. Another embodiment of this invention includes microposts inside the microfluidic channel for particle separation, rather than using microbeads. The silicon microposts can be built inside of silicon microfluidic channel by MEMS technology. The size of microposts can vary depending on the application. The microposts function as an in-line filter to block unwanted big particles and protect the microfluidic chip. Furthermore, micropost chips with microvalves can physically select different size cells, molecules, viruses etc. It can also be used to select different particles in bioengineering and pharmaceutical testing.
Miniaturized Laser Heterodyne Radiometer
This instrument uses a variation of laser heterodyne radiometer (LHR) to measure the concentration of trace gases in the atmosphere by measuring their absorption of sunlight in the infrared. Each absorption signal is mixed with laser light (the local oscillator) at a near-by frequency in a fast photoreceiver. The resulting beat signal is sensitive to changes in absorption, and located at an easier-to-process RF frequency. By separating the signal into a RF filter bank, trace gas concentrations can be found as a function of altitude.
Real-Time LiDAR Signal Processing FPGA Modules
The developed FPGA modules discern time-of-flight of laser pulses for LiDAR applications through the correlation of a Gaussian pulse with a discretely sampled waveform from the LiDAR receiver. For GRSSLi, up to eight cross-correlation engines were instantiated within a FPGA to process the discretely sampled transmit, receive pulses from the LiDAR receiver, and ultimately measure the time-of-flight of laser pulses at 20-picosecond resolution. Engine number is limited only by the resources within the FPGA fabric, and is configurable with a constant. Thus, potential time-of-flight measurement rates could go well beyond the 200-KHz mark required by GRSSLi. Additionally, the engines have been designed in an extremely efficient manner and utilize the least amount of FPGA resources possible.
Novel Superconducting Transition Edge Sensor
NASA technologists have developed several devices using this TES design. For example, innovators at NASA Goddard Space Flight Center have implemented an integrated system for defining the frequency response for dual- polarized microwave sensors for observations of the cosmic microwave background (CMB) in order to probe the evolution of the early universe. Precision measurement of the polarization of the CMB enables a direct test for cosmic inflation. Cosmological observations have have hinted that the universe experienced a brief period of rapid expansion called inflation early in its history that is believed to be responsible for the flatness of the universe and the origin of structure. If inflation occurred, it would have produced a gravitational wave background that is evidenced by a small but distinct polarized signature on the cosmic microwave background. The detector for CMB polarization measurements uses large format arrays of background-limited detectors in the form of feedhorn-coupled, TES based sensors. Each linear orthogonal polarization from the feedhorn is coupled to a superconducting microstrip line via a symmetric planar orthomode transducer (OMT). The symmetric OMT design allows for highly symmetric beams with low cross-polarization over a wide bandwidth. In addition, this architecture enables a single microstrip filter to define the passband for each polarization.
Remote Sensing Based on Fluorescence LIDAR
As originally developed, BILI is a novel planetary Astrobiology instrument based on a real-time technique of remote detection and discrimination of bio-signatures dispersed in the ground-level planetary atmosphere, leveraging the fluorescence lidar technology. Capabilities of this first planetary atmospheric bio-indicator survey instrument will dramatically increase the probability of finding the signatures of extraterrestrial life by performing atmospheric volume scans of hundreds of meters in a radial direction around the rover or lander. The Bio-Indicator Lidar technology employs real-time aerosol particle detection and discrimination based on two physical variables: particle fluorescence and particle size in the bio-discrimination space.
Gas Composition Sensing Using Carbon Nanotube Arrays
An array of carbon nanotubes (CNTs) in a substrate is connected to a variable-pulse voltage source. The CNT tips are spaced appropriately from the second electrode maintained at a constant voltage. A sequence of voltage pulses is applied and a pulse discharge breakdown threshold voltage is estimated for one or more gas components, from an analysis of the current-voltage characteristics. Each estimated pulse discharge breakdown threshold voltage is compared with known threshold voltages for candidate gas components to estimate whether at least one candidate gas component is present in the gas. The procedure can be repeated at higher pulse voltages to estimate a pulse discharge breakdown threshold voltage for a second component present in the gas. The CNTs in the gas sensor have a sharp (low radius of curvature) tip; they are preferably multiwall carbon nanotubes (MWCNTs) or carbon nanofibers (CNFs), to generate high-strength electrical fields adjacent to the current collecting plate, such as a gold plated silicon wafer or a stainless steel plate for breakdown of the gas components with lower voltage application and generation of high current. The sensor system can provide a high-sensitivity, low-power-consumption tool that is very specific for identification of one or more gas components. The sensors can be multiplexed to measure current from multiple CNT arrays for simultaneous detection of several gas components.
Detection Of Presence Of Chemical Precursors
These needs are met by this invention, which provide easy stem and associated method for detecting one or more chemical precursors (components) of a multi-component explosive compound. Different carbon nanotubes (CNTs) are loaded (by doping, impregnation, coating, or other functionalization process) for detecting of different chemical substances that are the chemical precursors, respectively, if these precursors are present in a gas to which the CNTs are exposed. After exposure to the gas, a measured electrical parameter (e.g. voltage or current that correlate to impedance, conductivity, capacitance, inductance, etc.) changes with time and concentration in a predictable manner if a selected chemical precursor is present, and will approach an asymptotic value promptly after exposure to the precursor. The measured voltage or current are compared with one or more sequence soft heir reference values for one or more known target precursor molecules, and a most probable concentration value is estimated for each one, two, or more target molecules. An error value is computed, based on differences of voltage or current for the measured and reference values, using the most probable concentration values. Where the error value is less than a threshold, the system concludes that the target molecule is likely. Presence of one, two, or more target molecules in the gas can be sensed from a single set of measurements.
Biomarker Sensor Arrays for Microfluidics Applications
This invention provides a method and system for fabricating a biomarker sensor array by dispensing one or more entities using a precisely positioned, electrically biased nanoprobe immersed in a buffered fluid over a transparent substrate. Fine patterning of the substrate can be achieved by positioning and selectively biasing the probe in a particular region, changing the pH in a sharp, localized volume of fluid less than 100 nm in diameter, resulting in a selective processing of that region. One example of the implementation of this technique is related to Dip-Pen Nanolithography (DPN), where an Atomic Force Microscope probe can be used as a pen to write protein and DNA Aptamer inks on a transparent substrate functionalized with silane-based self-assembled monolayers. But it would be recognized that the invention has a much broader range of applicability. For example, the invention can be applied to formation of patterns using biological materials, chemical materials, metals, polymers, semiconductors, small molecules, organic and inorganic thins films, or any combination of these.
Multidimensional Damage Detection System
The Damage Detection System consists of layered composite material made up of two-dimensional thin film damage detection layers separated by thicker, nondetection layers, coupled with a detection system. The damage detection layers within the composite material are thin films with a conductive grid or striped pattern. The conductive pattern can be applied on a variety of substrates using several different application methods. The number of detection layers in the composite material can be tailored depending on the level of damage detection detail needed for a particular application. When damage occurs to any detection layer, a change in the electrical properties of that layer is detected and reported. Multiple damages can be detected simultaneously, providing real-time detail on the depth and location of the damage. The truly unique feature of the System is its flexibility. It can be designed to gather as much (or as little) information as needed for a particular application using wireless communication. Individual detection layers can be turned on or off as necessary, and algorithms can be modified to optimize performance. The damage detection system can be used to generate both diagnostic and prognostic information related to the health of layered composite structures, which will be essential if such systems are utilized to protect human life and/or critical equipment and material.
electrical and electronics
Magnetic Shield Using Proximity Coupled Spatially Varying Superconducting Order Parameters
The invention uses the superconducting "proximity effect" and/or the "inverse proximity effect" to form a spatially varying order parameter. When designed to expel magnetic flux from a region of space, the proximity effect(s) are used in concert to make the superconducting order parameter strongly superconducting in the center and more weakly superconducting toward the perimeter. The shield is then passively cooled through the superconducting transition temperature. The superconductivity first nucleates in the center of the shielding body and expels the field from that small central region by the Meissner effect. As the sample is further cooled the region of superconducting order grows, and as it grows it sweeps the magnetic flux lines outward.