Tech Briefs

Mobile Underwater Acoustic Communications

This invention does not require any complicated signal processing.

Reliable, long-range acoustic communications (LRAC) is an enabling technology for numerous applications of manned and unmanned underwater systems. For example, with the capability of communicating at long ranges of several hundreds or even thousands of kilometers, it will become possible to remotely command and control unmanned underwater vehicles that are otherwise unreachable. As another example, underwater systems will be able to rely on such capability to establish a wide-area undersea network to complete missions in a collaborative fashion.

Posted in: Briefs, Communications, Telecommunications systems, Telecommunications systems, Acoustics, Acoustics, Marine vehicles and equipment

Three-Dimensional Zinc Electrode Architectures for High-Performance Batteries

Zinc-based batteries offer a safe, inexpensive alternative to fire-prone lithium-based batteries, yet have been historically limited by poor rechargeability. A 3D zinc (Zn) “sponge” electrode architecture was developed comprising interpenetrating networks of Zn scaffolding and void space. The design characteristics yield superior electrochemical properties when cycled in alkaline electrolytes compared to conventional Zn powder-composite electrodes.

Posted in: Briefs, Energy, Architecture, Batteries, Battery cell chemistry, Architecture, Batteries, Battery cell chemistry, Zinc alloys

Nanofabricated Devices Detect Ultrasound with Light

Tiny, soft, transparent, nanofabricated devices can be integrated into a contact lens.

The Micro-ring resonator detector can determine the speed of blood flow and the oxygen metabolic rate at the back of the eye. This information could help diagnose such common and debilitating diseases as macular degeneration and diabetes. The tiny, transparent device can fit into a contact lens, and could help a range of scientific endeavors from biomedicine to geology.

Posted in: Briefs, Test & Measurement, Optics, Sensors and actuators, Optics, Sensors and actuators, Diagnosis, Medical equipment and supplies, Fabrication, Nanotechnology

A Smooth-Walled Feedhorn with Sub-30-dB Cross-Polarization Over a 30-Percent Bandwidth

The focus of this research was the design, optimization, and measurement of a monotonically profiled, smooth-walled scalar feedhorn with a diffraction-limited ~14° FWHM (full width at half maximum). It is an easier-to-manufacture, smooth-walled feed that approximates the properties of excellent beam symmetry, main beam efficiency, and cross-polar response over wide band-widths, but over a finite bandwidth.

Posted in: Briefs, Communications, Optimization, Antennas, Radio equipment, Antennas, Radio equipment, Research and development

System for Repairing Cracks in Structures

This thermally activated coating heals cracks in metallic materials.

NASA’s Langley Research Center has developed an innovative coating to heal cracks in metal components, such as in aircraft and bridges. Currently, the coating is used for in-laboratory repairs of surface cracks. Development continues with the ultimate goal of an in-situ healing mechanism that can work autonomously with structural health monitoring detectors.

Posted in: Briefs, Coatings & Adhesives, Materials, Aircraft structures, Sensors and actuators, Sensors and actuators, Thermodynamics, Thermodynamics, Maintenance, Repair and Service Operations, Maintenance, repair, and service operations, Coatings Colorants and Finishes, Coatings, colorants, and finishes, Fatigue

Bio-Detection System is a Handheld Chemistry Lab

The device miniaturizes bench-scale analyses in a handheld, low-power device.

Devices for manipulating fluids on the microscale have been developed to store, hold, and manipulate small amounts of fluids, and have been applied to the detection of analytes in sample fluids. Manipulating fluids and performing capillary electrophoresis in microfluidic devices promises advantages of small size, high throughput, low sample volumes, and low cost.

Posted in: Briefs, Test & Measurement, Sensors and actuators, Sensors and actuators, Bacteria, Biological sciences, Chemicals, Materials identification

Wireless Virtual Reality Headset

This system allows VR headsets to communicate without a cord.

One of the limits of today's virtual reality (VR) headsets is that they must be tethered to computers in order to process data well enough to deliver high-resolution visuals. Wearing an HDMI cable reduces mobility, and can even lead to users tripping over cords. Researchers have developed a prototype system called MoVR that allows use of any VR headset wirelessly.

Posted in: Briefs, Communications, Virtual reality, Wireless communication systems, Wireless communication systems, Product development

Alpha-STREAM Convertor

Innovations offer a reliable and efficient way to generate power from any heat source.

Innovators at NASA’s Glenn Research Center have developed two novel technologies that make Stirling engines more efficient and less costly. First, Glenn’s thermoacoustic power converter uses sound to turn heat into electric power. Utilizing heat-driven pressures and volume oscillations from thermoacoustic sources to power piezoelectric alternators or other power-converter technologies, this device can generate electricity with unprecedented efficiencies. Unlike conventional Stirling-based devices, this thermoacoustic engine achieves high thermal-to-electrical efficiencies with no moving parts. Glenn’s second advancement for Stirling engines replaces the conventional linear alternator with a magnetostrictive alternator that converts the oscillating pressure wave into electric power (see figure). These innovations offer a reliable and efficient way to generate power from any heat source, benefiting applications such as combined heat and power (CHP) systems, distributed generation, solar power generation, and heating and cooling systems.

Posted in: Briefs, Energy, Alternators, Alternators, Electric power, Thermodynamics, Thermodynamics, Engine efficiency, Stirling engines

Aircraft Landing Noise Reduction Liners

The liners reduce aircraft noise that occurs during landing, helping aircraft comply with increasingly stringent airport noise restrictions.

NASA Langley Research Center has developed two new implementations of acoustic liners for aircraft noise reduction whereby curved channels within tight spaces can be outfitted to provide noise reduction. The two implementations are flap side edge liners and landing gear door liners for airframe noise reduction. In these applications, the acoustic liner is designed primarily to reduce aircraft noise that occurs during landing, which will help aircraft comply with increasingly stringent airport noise restrictions.

Posted in: Briefs, Aeronautics, Aerospace, Airframes, Noise, Noise, Entry, descent, and landing

Corrosion-Inhibiting Self-Expanding Foam

This anti-corrosion, self-expanding foam is designed for use in hard-to-protect internal structures.

Surfaces such as metal and other corrodible surfaces are often exposed to extreme weathering, temperatures, moisture, impurities, and otherwise damaging external forces that accelerate corrosion. Conventional methods of corrosion protection include applying paints and other coatings, such as petroleum-based undercoatings, with a sprayer to the exposed surface. To be effective, the entire exposed surface must be covered or the corrosion process will be accelerated at the unprotected areas. While open-area surfaces may be easier to protect, those surfaces found in internal cavities within an overall framework can be more challenging to protect. Achieving full coverage on internal surfaces can be extremely difficult, and in some cases impossible without drilling several access openings in the structure. These extraneous openings can compromise the strength of the structure as well as create more entryways for water and debris. This increases the opportunity for corrosion to initiate at the edges of the openings.

Posted in: Briefs, Coatings & Adhesives, Materials, Corrosion, Foams, Metals

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