February 05, 2019 Volume 15 Issue 05

Electrical/Electronic News & Products

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Slip rings improve Ethernet transmission

The Kuebler Group offers contact and contactless slip rings for reliable Ethernet transmission, achieving higher data rates and greater cycle synchronicity in demanding industrial environments. Application examples include industrial automation, bottling plants, labeling machines, rotary tables, and other processes requiring high transmission rates. The standard Slip Ring SR120 features an innovative three-chamber system and shield to enable parallel, interference-free Ethernet transmission up to 100 Mbps. It boasts a long service life up to 500 million revolutions and a rugged, modular structure that can be expanded up to 20 channels. Another model, the Slip Ring SR160 with integrated Sendix Encoder, provides position information in addition to contactless Ethernet transmission -- either two channels at 100 Mbps multiplexed or one channel at 1 Gbps.
Learn more.


How to convert from hydraulic to electric high-force linear actuators

Machine designers are converting existing linear motion systems from hydraulic to electric due to the technology's many benefits, but the process involves considering the actual force output of the cylinder, the duty cycle, and the motion profile. Specialists at Tolomatic tackle these points. Includes a very informative video.
Read the Tolomatic blog.


Integrate Alexa and more into your product or project

The MATRIX Voice Development Kit from MATRIX Labs aims to lower the barriers to entry for the creation and deployment of Internet of Things (IoT) voice applications. This platform enables users to develop voice recognition and detection projects that utilize Google Assistant or Amazon Alexa -- or any other voice recognition API. This open-source platform for the Raspberry Pi consists of a 3.14-in.-diameter development board, a radial array of 7 MEMS microphones, a Xilinx Spartan6 FPGA with 64 Mbit SDRAM, 18 RGBW LEDs, and 64 GPIO pins. It can also be used as a standalone device with the ESP32. Available from Newark element14.
Learn more from MATRIX Labs.
See purchase options from Newark element14.


Cool Tools: New Raspberry Pi Compute Module 3+

Newark element14 is now shipping the new Raspberry Pi Compute Module 3+ for same-day dispatch. Raspberry Pi Compute Module 3+ delivers the enhanced thermal performance and ease of use of Raspberry Pi 3 Model B+ in a smaller form factor, with a choice of memory variants suitable for a broad range of embedded applications including IoT devices and industrial automation, monitoring, and control systems. Compute Module 3+ simplifies the design process engineers need to undertake when developing a System on Module (SoM) solution into their final product. Engineers do not need to concern themselves with the complexities of interfacing with the BCM2837B0 processer directly and instead can concentrate on designing the interfaces to their own IO board and their application software -- simplicity that fosters rapid development.
Learn more.


360-degree static eliminator is CE, UL, and RoHS certified

EXAIR's new Gen4 Super Ion Air Wipe provides a uniform 360-degree ionized airstream that clamps around a continuously moving part to eliminate static electricity and contaminants. It is ideal for removing dust, particulates, and personnel shocks on pipe, cable, extruded shapes, hose, wire, and more. This engineered product has undergone independent lab tests to certify it meets the rigorous safety, health, and environmental standards to attain the CE and UL marks. It is also RoHS compliant. New design features include a metal armored high-voltage cable to protect against abrasion and cuts, a replaceable emitter point, integrated ground connection, and electromagnetic shielding.
Learn more.


20-in. automotive touchscreens enabled by new controllers

With cars like the Tesla Model S featuring 17-in. touchscreens, the trend in automotive displays is to go bigger and bigger. But unlike handheld mobile devices, screens in automobiles need to meet stringent head impact and vibration tests, so they have thicker cover lenses that potentially affect the touch interface performance. As screens get larger, they are also more likely to interfere with other frequencies and car access systems. These factors pose a major challenge in the design of modern automotive capacitive touch systems, but a new family of single-chip maXTouch touchscreen controllers from Microchip Technology was designed to address these issues.
Learn more.


Electric high-force linear actuator choices: Ball vs. roller screw

Many applications require high-force linear actuators -- from moving equipment in a foundry to powering a press in metal forming to guiding heavy logs in a sawmill. Whatever the application, a machine designer is faced with a choice: whether to specify a ball or roller screw in the electric high-force linear actuator. Learn how to make the best decision for your application.
Read the Tolomatic blog.


Big additions to miniature LED product line

Thanks to the recent acquisition of Display Products, Inc. (DPP), VCC is offering LEDs that drive energy-saving solutions for a range of applications. In mid-October, VCC announced the first wave of available replacement LED products, including the bi-pin model of the T-2 Slide Based LED Lamp. Now, the innovative company is making additional models available to provide several benefits for manufacturers, designers, and even end users seeking ways to improve efficiency and reduce maintenance costs. This next wave of rollouts includes T-2 Slide Based LED lamps in voltages ranging from 12V to 120VAC, as well as the new and noteworthy T-3 1/4 Miniature LEDs.
Learn more.


Flexible circuit design guide

Tech-Etch uses advanced techniques to manufacture flex and rigid-flex circuits to exacting customer specifications. Special processes include selective plating a single circuit with two different finishes, contoured circuits with variable metal thickness, semi-additive and subtractive techniques, open window or cantilevered contact leads, plus SMT for component assembly. Tech-Etch specializes in flexible circuits for medical device, medical implant, diagnostic ultrasound, and patient monitoring applications, in addition to telecommunications, aerospace, semiconductor, and other high-reliability electronic applications.
Learn about flex circuits and download the guide (no registration required).


Power supply for servos with power factor correction

ADVANCED Motion Controls has introduced the PFC2400W375, a regulated DC power supply designed to feed 400-V series servo drives with a low-noise 375-VDC bus. Universal single-phase AC input 100-240 VAC/50-60 Hz with power factor correction and low harmonic distortion along with soft starting circuitry guarantees global high-performance, reliable operation. This new power supply is designed to achieve power factor improvement, improve performance, and ensure consistent operation regardless of the local power company's voltage levels and quality.
Learn more.


World's smallest safety laser scanner

A laser scanner is a safety device that uses the reflection of laser beams to detect the presence of objects or people. The SE2L Safety Laser Scanner from IDEC is the world's smallest unit of its kind -- and the world's first with master/slave functionality and dual protection zones. This scanner is certified for use in safety applications including AGVs, forklifts, robots, and other items of moving equipment found in industrial facilities.
Learn more.


See further at higher sensitivity: Advanced, lightweight infrared camera core for imaging gimbals

Sierra-Olympic Technologies, a supplier of infrared (IR) and thermal imaging components, cameras, and systems solutions, has just introduced the Ventus 275, a midwave-infrared imaging engine with a continuous zoom (CZ) optic. Advanced image enhancements include electronic image stabilization, automatic/manual gain control, adaptive contrast control, and optional target tracking/detection. This compact, lightweight MWIR thermal camera core is specially designed for OEM integrators of surveillance system enclosures and other imaging gimbals.
Learn more.


1000Base-T1 automotive Ethernet common mode choke

Pulse Electronics' Networking Business Unit has introduced the 1000Base-T1 Ethernet Common Mode Choke for automotive applications. Designed to deliver high reliability and performance, the AE5002 1000Base-T1 series is ideal for applications such as Infotainment, Advanced Driver Assist Systems (ADAS) Body Control, Camera/Radar, Gateways, and Backbone Diagnostics.
Learn more.


Cool Tools: Minimally invasive video borescope

Extech Instruments has launched the BR250-4, an affordable and versatile wireless inspection borescope designed to get into openings as small as 4.5 mm while providing bright clear images on its detachable, wireless 3.5-in. color display. When you need to get into walls, ducts, furnaces, boiler tubes, air handlers, exchangers, coils, plenums, and other concealed or hard-to-access areas, this is your hero. And when there's no existing opening and drilling is required, making a much smaller hole leaves minimal damage.
Learn more.


Drop-in solution makes your machine ready for Industry 4.0

Bosch Rexroth's IoT Gateway Rack is an IP65-rated enclosure containing Rexroth's award-winning IoT Gateway. It includes all the necessary wiring and connections to connect PLCs, I/O, and other data sources for collection, processing, and forwarding of plant floor data to upper-level data systems, making it ideal for retrofitting older machines with Industry 4.0 data-transfer capabilities. The plug-and-play design allows OEMs to use the IoT Gateway Rack as an optional addition to their existing machines. Uses standard 110-V plug.
Learn more.


New battery-free 'rectenna' converts Wi-Fi signals to electricity using 2D materials

A device made from flexible, inexpensive materials could power large-area electronics, wearables, medical devices, and more.

By Rob Matheson, MIT

Imagine a world where smartphones, laptops, wearables, and other electronics are powered without batteries. Researchers from MIT and elsewhere have taken a step in that direction, with the first fully flexible device that can convert energy from Wi-Fi signals into electricity that could power electronics.

Devices that convert AC electromagnetic waves into DC electricity are known as "rectennas." The researchers demonstrate a new kind of rectenna, described in a study appearing in Nature Jan. 28, 2019, that uses a flexible radio-frequency (RF) antenna that captures electromagnetic waves -- including those carrying Wi-Fi -- as AC waveforms.

The antenna is then connected to a novel device made out of a two-dimensional semiconductor just a few atoms thick. The AC signal travels into the semiconductor, which converts it into a DC voltage that could be used to power electronic circuits or recharge batteries.

Researchers from MIT and elsewhere have designed the first fully flexible, battery-free "rectenna" -- a device that converts energy from Wi-Fi signals into electricity. [Image: Christine Daniloff]

 

 

 

 

In this way, the battery-free device passively captures and transforms ubiquitous Wi-Fi signals into useful DC power. Moreover, the device is flexible and can be fabricated in a roll-to-roll process to cover very large areas.

"What if we could develop electronic systems that we wrap around a bridge or cover an entire highway, or the walls of our office and bring electronic intelligence to everything around us? How do you provide energy for those electronics?" says paper co-author Tomás Palacios, a professor in the Department of Electrical Engineering and Computer Science and director of the MIT/MTL Center for Graphene Devices and 2D Systems in the Microsystems Technology Laboratories. "We have come up with a new way to power the electronics systems of the future -- by harvesting Wi-Fi energy in a way that's easily integrated in large areas -- to bring intelligence to every object around us."

Promising early applications for the proposed rectenna include powering flexible and wearable electronics, medical devices, and sensors for the Internet of Things. Flexible smartphones, for instance, are a hot new market for major tech firms. In experiments, the researchers' device can produce about 40 microwatts of power when exposed to the typical power levels of Wi-Fi signals (around 150 microwatts). That's more than enough power to light up an LED or drive silicon chips.

Another possible application is powering the data communications of implantable medical devices, says co-author Jesús Grajal, a researcher at the Technical University of Madrid. For example, researchers are beginning to develop pills that can be swallowed by patients and stream health data back to a computer for diagnostics.

"Ideally you don't want to use batteries to power these systems, because if they leak lithium, the patient could die," Grajal says. "It is much better to harvest energy from the environment to power up these small labs inside the body and communicate data to external computers."

All rectennas rely on a component known as a "rectifier," which converts the AC input signal into DC power. Traditional rectennas use either silicon or gallium arsenide for the rectifier. These materials can cover the Wi-Fi band, but they are rigid. And, although using these materials to fabricate small devices is relatively inexpensive, using them to cover vast areas, such as the surfaces of buildings and walls, would be cost-prohibitive. Researchers have been trying to fix these problems for a long time. But the few flexible rectennas reported so far operate at low frequencies and can't capture and convert signals in gigahertz frequencies, where most of the relevant cell phone and Wi-Fi signals are.

To build their rectifier, the researchers used a novel 2D material called molybdenum disulfide (MoS2), which at three atoms thick is one of the thinnest semiconductors in the world. In doing so, the team leveraged a singular behavior of MoS2: When exposed to certain chemicals, the material's atoms rearrange in a way that acts like a switch, forcing a phase transition from a semiconductor to a metallic material. The resulting structure is known as a Schottky diode, which is the junction of a semiconductor with a metal.

"By engineering MoS2 into a 2D semiconducting-metallic phase junction, we built an atomically thin, ultrafast Schottky diode that simultaneously minimizes the series resistance and parasitic capacitance," says first author and EECS postdoc Xu Zhang, who will soon join Carnegie Mellon University as an assistant professor.

Parasitic capacitance is an unavoidable situation in electronics where certain materials store a little electrical charge, which slows down the circuit. Lower capacitance, therefore, means increased rectifier speeds and higher operating frequencies. The parasitic capacitance of the researchers' Schottky diode is an order of magnitude smaller than today's state-of-the-art flexible rectifiers, so it is much faster at signal conversion and allows it to capture and convert up to 10 gigahertz of wireless signals.

"Such a design has allowed a fully flexible device that is fast enough to cover most of the radio-frequency bands used by our daily electronics, including Wi-Fi, Bluetooth, cellular LTE, and many others," Zhang says.

The reported work provides blueprints for other flexible Wi-Fi-to-electricity devices with substantial output and efficiency. The maximum output efficiency for the current device stands at 40 percent, depending on the input power of the Wi-Fi input. At the typical Wi-Fi power level, the power efficiency of the MoS2 rectifier is about 30 percent. For reference, today's rectennas made from rigid, more expensive silicon or gallium arsenide achieve around 50 to 60 percent.

"This very nice teamwork from MIT demonstrates the first real application [of] atomically thin semiconductors for a flexible rectenna for energy harvesting," says Philip Kim, a professor of physics and applied physics at Harvard University whose research focuses on 2D materials. "I am amazed by the innovate approach that the team has set up to utilize the waste energy from RF power around us."

There are 15 other paper co-authors from MIT, Technical University of Madrid, the Army Research Laboratory, Charles III University of Madrid, Boston University, and the University of Southern California.

The team is now planning to build more complex systems and improve efficiency. The work was made possible, in part, by a collaboration with the Technical University of Madrid through the MIT International Science and Technology Initiatives (MISTI). It was also partially supported by the Institute for Soldier Nanotechnologies, the Army Research Laboratory, the National Science Foundation's Center for Integrated Quantum Materials, and the Air Force Office of Scientific Research.

Published February 2019

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