Special Coverage

Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines
Vibration Tables Shake Up Aerospace and Car Testing
Supercomputer Cooling System Uses Refrigerant to Replace Water

NASA-Inspired Shape-Sensing Fibers Enable Minimally Invasive Surgery

Minimally Invasive Surgery (MIS) is a new class of surgical procedures in which the operation is performed with surgical instruments inserted through small incisions in the body. In contrast to open surgery, in which the organ or tissue is exposed through large incisions in the body, MIS procedures generally allow for faster recovery time, less pain and trauma, reduced risk of infection, and shorter hospital stays.

Posted in: Articles, Materials, Medical, Sensors, Surgical procedures, Fibers

SiO₂/TiO₂ Composite for Removing Hg From Combustion Exhaust

This material could remove mercury from exhaust streams of coal-burning power plants.

Pellets made of a high-surface-area composite of silica and titania have shown promise as means of removing elemental mercury from flue gases. With further technical development and commercialization, this material could become economically attractive as a more-effective, less-expensive alternative to activated carbons for removing mercury from exhaust streams of coal-burning power plants, which are the sources of more than 90 percent of all anthropogenic airborne mercury.

Posted in: Briefs, Materials, Coal gasification, Composite materials, Gases, Particulate filters, Hazardous materials

Lightweight Tanks for Storing Liquefied Natural Gas

These tanks are also relatively inexpensive.

Single-walled, jacketed aluminum tanks have been conceived for storing liquefied natural gas (LNG) in LNG-fueled motor vehicles. Heretofore, double- wall steel tanks with vacuum between the inner and outer walls have been used for storing LNG. In comparison with the vacuum-insulated steel tanks, the jacketed aluminum tanks weigh less and can be manufactured at lower cost. Costs of using the jacketed aluminum tanks are further reduced in that there is no need for the vacuum pumps heretofore needed to maintain vacuum in the vacuum-insulated tanks.

Posted in: Briefs, Materials, Natural gas, Product development, Aluminum, Fuel tanks

Hybrid Wound Filaments for Greater Resistance to Impacts

PBO fibers are used in addition to high-strength carbon fibers.

The immediately preceding article includes an example in which a composite overwrap on a pressure vessel contains wound filaments made of a hybrid of high-strength carbon fibers and poly(phenylene benzobisoxazole) [PBO] fibers. This hybrid material is chosen in an effort to increase the ability of the pressure vessel to resist damage by lowspeed impacts (e.g., dropping of tools on the vessel or bumping of the vessel against hard objects during installation and use) without significantly increasing the weight of the vessel. Heretofore, enhancement of the impact resistances of filament-wound pressure vessels has entailed increases in vessel weight associated, variously, with increases in wall thickness or addition of protective materials.

Posted in: Briefs, Materials, Containers, Composite materials, Fibers, Impact tests

Making High-Tensile-Strength Amalgam Components

Instead of spheroids or flakes, wires are used as the solid constituents.

Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room- temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles.

Posted in: Briefs, Materials, Aircraft structures, Body structures, Forming, Materials properties, Metals, Tensile Strength

Bonding by Hydroxide-Catalyzed Hydration and Dehydration

Room-temperature process can be varied to suit optical and non-optical applications.

A simple, inexpensive method for bonding solid objects exploits hydroxidecatalyzed hydration and dehydration to form silicatelike networks in thin surface and interfacial layers between the objects. (Silicatelike networks are chemical-bond networks similar to, but looser than, those of bulk silica). The method can be practiced at room temperature or over a wide range of temperatures.

Posted in: Briefs, Materials, Joining, Chemicals

CHEM-Based Self-Deploying Planetary Storage Tanks

A document proposes self-deploying storage tanks, based on the cold elastic hibernated memory (CHEM) concept, to be used on remote planets. The CHEM concept, described in previous NASA Tech Briefs articles, involves the use of open-cell shape-memory-polymer (SMP) foam sandwich structures to make lightweight, space-deployable structures that can be compressed for storage and can later be expanded, then rigidified for use.

Posted in: Briefs, TSP, Materials, Containers, Storage, Foams

Sequestration of Single-Walled Carbon Nanotubes in a Polymer

The nanotubes would be solubilized for incorporation into lightweight composites.

Sequestration of single-walled carbon nanotubes (SWCNs) in a suitably chosen polymer is under investigation as a means of promoting the dissolution of the nanotubes into epoxies. The purpose of this investigation is to make it possible to utilize SWCNs as the reinforcing fibers in strong, lightweight epoxy-matrix/ carbon-fiber composite materials. SWCNs are especially attractive for use as reinforcing fibers because of their stiffness and strength-to-weight ratio: Their Young’s modulus has been calculated to be 1.2 TPa, their strength has been calculated to be as much as 100 times that of steel, and their mass density is only one-sixth that of steel.

Posted in: Briefs, Materials, Composite materials, Fibers, Nanotechnology, Polymers

Foam Core Shielding for Spacecraft

A foam core shield (FCS) system is now being developed to supplant multilayer insulation (MLI) systems heretofore installed on spacecraft for thermal management and protection against meteoroid impacts. A typical FCS system consists of a core sandwiched between a face sheet and a back sheet. The core can consist of any of a variety of low-to- medium-density polymeric or inorganic foams chosen to satisfy application-specific requirements regarding heat transfer and temperature.

Posted in: Briefs, Materials, Thermal management, Thermal management, Foams, Spacecraft

Modeling Metamaterials Leads to Advance in Cloaking System Prototype

In efforts to use metamaterials to construct the world’s first working prototype of an invisibility cloak, researchers relied on multiphysics software.

Modeling software is generally used to show the fields and flows that are impossible to see with the eye or instruments. A group of researchers has done just the opposite: They ran computer simulations that showed it should be possible to fabricate the metamaterials necessary to build an “invisibility cloak” that makes an object invisible to certain frequencies.

Posted in: Briefs, Materials, Computer simulation, Research and development, Visibility

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.