Electronics & Computers

Researchers Control Surface Tension of Liquid Metals

Researchers from North Carolina State University have developed a technique for controlling the surface tension of liquid metals by applying very low voltages, opening the door to a new generation of reconfigurable electronic circuits, antennas and other technologies. The technique hinges on the fact that the oxide “skin” of the metal – which can be deposited or removed – acts as a surfactant, lowering the surface tension between the metal and the surrounding fluid.The researchers used a liquid metal alloy of gallium and indium. In base, the bare alloy has a remarkably high surface tension of about 500 millinewtons (mN)/meter, which causes the metal to bead up into a spherical blob. “But we discovered that applying a small, positive charge – less than 1 volt – causes an electrochemical reaction that creates an oxide layer on the surface of the metal, dramatically lowering the surface tension from 500 mN/meter to around 2 mN/meter,” says Dr. Michael Dickey, an associate professor of chemical and biomolecular engineering at NC State and senior author of a paper describing the work. “This change allows the liquid metal to spread out like a pancake, due to gravity.”The researchers also showed that the change in surface tension is reversible. If researchers flip the polarity of the charge from positive to negative, the oxide is eliminated and high surface tension is restored.  The surface tension can be tuned between these two extremes by varying the voltage in small steps.SourceAlso: Learn about Gradient Metal Alloys Fabricated Using Additive Manufacturing.

Posted in: Electronics & Computers, Electronics, Power Management, Materials, Metals, RF & Microwave Electronics, Antennas, News

Read More >>

Dust Removal from Solar Cells

This system is easily integrated with current solar cell panel designs. John H. Glenn Research Center, Cleveland, Ohio Photovoltaic cell arrays are used on robotic rovers on the Mars surface, but dust accumulation on the surface of the solar cells reduces their exposure to light radiation and thus degrades their performance. Dust that accumulates without being removed limits the life of the rover’s power systems. Similarly, terrestrial solar arrays suffer from dust accumulation, especially when located in desert areas, which reduces their effectiveness. Technologies for re moval of the dust or preventing it from settling have been proposed and are being researched, but none were yet implemented on the rovers. These techniques include mechanical means, blowing stored gas, blowing pumped gas, electrically charging the surface, repelling the dust, and other techniques.

Posted in: Electronics & Computers, Briefs

Read More >>

Minimally Obstructed Communication via Acoustic Modems in Fluid-Filled Pipes

This technology can be used in the oil industry, as well as in various underwater operations. NASA’s Jet Propulsion Laboratory, Pasadena, California An acoustic modem that uses a separate phased-array transmitter and receiver has been conceived that allows the communication of high-frequency acoustic waves sideways to the transducer along the fluid-filled pipe. The transducer allows directing waves between the transmitter and the receiver with potentially minimal interferences with the piping walls. In addition, another method of directly sending communication signals up- and down-hole has been conceived that uses angled piezoelectric ring transducers.

Posted in: Electronics & Computers, Briefs

Read More >>

Biofeedback System for Optimal Athletic Performance

Langley Research Center, Hampton, Virginia ZONE (Zeroing Out Negative Effects) is a method of biofeedback training for optimal athletic performance. ZONE is designed to improve athletes’ responses to stress, anxiety, and loss of concentration during competition. In the training environment, when the user successfully attains an optimal target state of psychophysiological functioning, the technology informs and/or rewards the user through real-time physical changes in the athletic equipment. For example, in the training setting, a golfer can work toward optimal concentration in the act of putting, leading to improved performance in real situations.

Posted in: Electronics & Computers, Briefs

Read More >>

Methods for Clock and Reset Synchronization in a CMOS Integrated Circuit

These methods ensure fault-free operation in high-integrity systems. Lyndon B. Johnson Space Center, Houston, Texas In high-integrity systems, a method of assuring integrity called a self-checking pair is employed. A self-checking pair is a logical grouping of two of the same devices performing the same operation and cross-checking each other to ensure correct operation. In this manner, a single fault on one will be detected by its partner, and the appropriate action can be taken to both recover the fault and ensure the fault does not propagate.

Posted in: Electronics & Computers, Briefs

Read More >>

Wideband MMIC Distributed Amplifier-Based Microwave Power Module

The solid-state module operates as a radar, communication, or navigation system. John H. Glenn Research Center, Cleveland, Ohio This innovation is a wideband, high-power, high-efficiency, all-solid-state microwave power module (SSMPM) or amplifier for a multifunction spacecraft payload that operates, depending on the need, as a radar system, communication system, or navigation system. The construction of the module is based on a wideband multi-stage amplifier design. The low-power stage is a high-efficiency GaAs pHEMT-based MMIC (monolithic microwave integrated circuit) distributed amplifier. The medium-power stage is either a high-efficiency GaAs pHEMT (high-electron-mobility transistor) or GaN HEMT-based MMIC distributed amplifier. The high-power stage is a high-efficiency GaN HEMT-based MMIC distributed amplifier.

Posted in: Electronics & Computers, Briefs

Read More >>

Communication Monitoring System for Enhanced Situational Awareness

A number of innovations are used to increase situational awareness and reduce operator fatigue. Ames Research Center, Moffett Field, California The system and method of reconfigurable Auditory-Visual Display creates a multi-mode communications environment with the express intent of increasing situational awareness for the operator (controller), and for reducing operator fatigue. Situational awareness is increased by a number of innovations, such as spatially separating each voice communication channel and allowing a single voice channel to be prioritized, while still allowing other channels to be monitored. The controller can see real-time video from each of the controlled individuals, and sensor data from these individuals can be collected electronically rather than being presented over a voice channel. It also provides the controlling individual an interface to record and transmit event data.

Posted in: Electronics & Computers, Briefs

Read More >>

White Papers

Guidelines for Ensuring PCB Manufacturability
Sponsored by Sunstone Circuits
Epoxies and Glass Transition Temperature
Sponsored by Master Bond
Spherical Plain Bearing
Sponsored by AST Bearings
Uncooled Infrared Imaging: Higher Performance, Lower Costs
Sponsored by Sofradir EC
Multi-Purpose Non-Contact Position/Displacement Sensing
Sponsored by Kaman
Improving Cable Performance in Harsh Environments
Sponsored by Gore

White Papers Sponsored By: