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Health Medicine and Biotechnology
Electrochemical Sensors Based on Enzyme-Linked Immunosorbent Assay
NASA’s electrochemical Enzyme-Linked Immunosorbent Assay (ELISA) microelectrode array biosensor advantageously incorporates a microbead detection construct, coupled with a magnetic immobilization construct, which substantially increases the signal sensitivity of a sensor. The magnetic immobilization construct draws the microbead detection construct to an electrode detection surface, enhancing signal sensitivity. By concentrating the signaling molecules close to the electrode detection surface, electrochemical redox cycling is achieved by reducing the distance between the two, allowing for regeneration of reporter molecules.
Whereas a traditional ELISA testing exhibits five to ten signaling molecules per probe molecule binding event, the present electrochemical ELISA-based biosensor testing exhibits up to 4,857 signaling molecules per probe molecule binding event. The model bead construct exhibits a more than 6.75-fold in increased measured signal, and more than 35.7-fold improvement in signal sensitivity. When compared to traditional optical ELISA, the present invention improves the limit of detection by up to a factor of 60.5.
NASA’s electromagnetic ELISA-based biosensor can be used for the detection of SARS-CoV-2 virus to enhance Covid-19 testing during the early phases of infection. The technology may also be modified to detect other biomarkers.
Optics
Fingerprinting for Rapid Battery Inspection
The technology utilizes photopolymer droplets (invisible to the digital radiograph) with embedded radiopaque fragments to create randomized fingerprints on battery samples. The droplets are deposited using a jig (see figure on right) that precisely positions samples. Then, at different points during battery R&D testing or use, digital radiography imaging with micron-level resolution can be performed.
The high-resolution imaging required to detect dendrite formation requires images to be collected in multiple “tiles” as shown below. The randomized fingerprints uniquely identify relative positioning of these tiles, allowing rapid assembly of composite high-resolution images from multiple tiles.
This same composite creation process can be used for images taken at a series of points in time during testing, and background subtraction can be applied to efficiently compare how the battery is changing over successive charge/discharge cycles to identify dendrite formation. This inspection technique is proven effective for thin-film pouch cell prototypes at NASA, and it works well at the lowest available x-ray energy level (limiting impact on the samples). The Fingerprinting for Rapid Battery Inspection technology is available for patent licensing.
instrumentation
Calculation of Unsteady Aerodynamic Loads Using Fast-Response Pressure-Sensitive Paint (PSP)
Traditionally, unsteady pressure transducers have been the instrumentation of choice for investigating unsteady flow phenomena which can be time-consuming and expensive. The ability to measure and compute these flows has been a long-term challenge for aerospace vehicle designers and manufacturers. Results using only the pressure transducers are prone to inaccuracies, providing overly conservative load predictions in some cases and underestimating load predictions in other areas depending on the flow characteristics. NASA Ames has developed a new state-of-the-art method for measuring fluctuating aerodynamic-induced pressures on wind tunnel models using unsteady Pressure Sensitive Paint (uPSP). The technology couples recent advances in high-speed cameras, high-powered energy sources, and fast response pressure-sensitive paint. The unsteady pressure-sensitive paint (uPSP) technique has emerged as a powerful tool to measure flow, enabling time-resolved measurements of unsteady pressure fluctuations within a dense grid of spatial points on a wind tunnel model. The invention includes details surrounding uPSP processing. This technique enables time-resolved measurements of unsteady pressure fluctuations within a dense grid of spatial points representing the wind tunnel model. Since uPSP is applied by a spray gun, it is continuously distributed. With this approach, if the model geometry can be painted, viewed from a camera, and excited by a lamp source, uPSP data can be collected. Unsteady PSP (uPSP) has the ability to determine more accurate integrated unsteady loads.