Research Terms
Superconducting and Magnetic Materials Magnetism Magnetic Technology
Industries
The present invention describes thin film sensors for detecting the presence, intensity, and/or location of a compressive force, or pressure based on ionic conduction variation as the sensing principle. Upon wisely choosing soft materials-- elastomer-like polymer and polymeric gel electrolytes/polymer electrolytes in combination with appropriate patterning, the present invention offers low pressure level sensing and mapping capability with enhanced sensitivity. The sensor includes a plurality of conducting elements spaced apart from each other and at least one deformable electrolyte bridge contacting each of the conducting elements at one or more contact points having an aggregate contact area. Upon formation of an ionic circuit between two of the conducting elements, a first resistivity between the two conducting element exists. Upon application of a compressive force on the at least one deformable electrolyte bridge directed toward at least one of the conducting elements, the aggregate contact area increases such that a second resistivity between the two conducting elements exists. The difference between the first and second resistivity can be correlated with the pressure or mechanical displacement to be measured.
Available for licensing is a simple, scalable oxidation process that improves industrial magnet design and performance.
Rare earth barium copper oxide (REBCO) is a high temperature superconductor. REBCO wire holds the promise of making very high field magnets which find commercial applications in nuclear magnetic resonance (NMR), the food and drug industry, as well as applications in large international research facilities such as particle accelerators.
Usually, magnet coils are made by winding insulated conductor wires. Due to the unique properties of REBCO wire, a coil made by insulated REBCO is prone to damage in magnet operation. Therefore, a no-insulation coil technology has been developed recently taking advantage of the fact that the resistive short circuit does not interfere the superconducting current path. Removing insulation results in very high efficiency and allows scientists and engineers to design extremely high field magnets that are exceptionally compact.
However, a coil with no insulation has the drawbacks of longer magnet charging times and a higher consumption rate of expensive cryogen, such as liquid helium. This is directly related to its low contact resistance (Rc) between adjacent turns in the coil made by commercial REBCO conductors. In order to mitigate the issues of no-insulation magnets, it is critically important to control turn-to-turn contact resistance.
Dr. Jun Lu at the National High Magnetic Field Laboratory has developed a process for oxidizing REBCO wire surface to achieve a controllable turn-to-turn contact resistance. With this technology, magnets can be charged quickly, and have low cryogen consumption. Meanwhile, it retains the advantage of the no-insulation coil technology which leads to very high magnetic field, coil self-protection and a very compact magnet design.
Stainless steel tapes are dip coated with a tape withdrawal speed of ~16 mm/s, dried at ~300 °C for 10-20 seconds, followed by a calcination process at 600 °C. This system consists of a pay-off and a take-up spool with a driving mechanism, a vertical two zone furnace, and a dip tank. The sol-gel solution to powder loading ratio was fixed at a composition that contained enough sol-gel solution to bind the powder to produce thick and adherent coating.