Robot Dog Astro Can Sit, Lie Down, and Save LivesYou Can’t Squish This Cockroach-Inspired Robot Stay on target The U.S. Army is taking cues from invertebrates to create more flexible robots.A joint project between the Army Research Laboratory (ARL) and University of Minnesota (UMN) sought inspiration from spineless animals like insects, crustaceans, mollusks, echinoderms, jellyfish, and worms.The Army uses structurally rigid robots—great for protecting soldiers and machinery, but rather impractical for operations that require covert handling.AdChoices广告“Successful stealthy maneuvering requires high structural flexibility and distributive control to sneak into confined or restricted spaces, operate for extended periods, and emulate biological morphologies and adaptability,” Ed Habtour, ARL researcher who specialized in nonlinear structural dynamics, said in a statement.Existing military bots, he explained, have two major limitations: a lack of dynamic flexibility, and complex mechanisms and electrical circuitries. To overcome these handicaps, teams from ARL and UMN turned to nature.Their initial research sired soft actuator prototypes—the first fully 3D-printed dielectric elastomer actuator (DEA) that can perform high bending motion.Habtour et al., however, were not first to arrive at the soft robot party: Mimicking real octopuses, Harvard scientists in 2016 created the original soft robot, Octobot.Built using a combination of 3D printing, pneumatics, and chemical reactions, Octobot’s limbs move, but don’t actually drive the cyborg; the simple proof of concept is not mobile or capable of interacting with its environment.Still, a glowing, pliable octopus is pretty cool.There is no telling what the Army will make with their newfound technology—a bionic crab? An automated jellyfish?ARL is still in the early stages of development, their research published recently in the journal Extreme Mechanics Letters.“The research findings represent an important stepping stone towards providing the soldier an autonomous freeform fabrication platform—next-generation 3D printer, which can print functional materials and devices—to generate soft actuators and potentially tetherless soft robots on demand, on the fly, and at the point of need,” Habtour said.
Multifunction mirror. This metamaterial mirror reflects light with the resonant frequency at an angle determined by the placement of antenna-like omega inclusions of various designs. The blue beam strikes the mirror at a right angle but is reflected at 45 degrees. For the red beam, which has a different frequency, the metamirror is transparent. Credit: V. Asadchy/Aalto Univ/ Physics Magnetic mirrors enable new technologies by reflecting light in uncanny ways Normal mirrors reflect light back at an equal but opposite angle, which works well for some purposes. Over the past several years, scientists have discovered that applying metamaterials to the surface of a regular mirror allows for manipulating the reflective angle. In this new effort, the researchers have found that metamaterials could be used both for manipulating certain frequencies and for reflecting purposes while at the same time allowing other frequencies of light to pass through unchanged. With such a mirror it would be possible, for example, to make a mirror/window that allows normal and infrared light through, but not ultraviolet.In their work, the researchers found that embedding tiny copper wires (which they call inclusions) inside of a clear material that normally allowed microwaves to pass through allowed them to create a mirror that could be used to reflect microwaves in ways they chose while also allowing light and other radiation to pass through unchanged. By manipulating the size and shape of the inclusion, the researchers could choose the frequency they wanted to impact and the reflection angle. The technique works, they explain because the microwaves cause the tiny wires to oscillate at the same frequency as the original microwaves, but only for a very short time—they are very soon released at the same frequency, but travel in a different direction. The team also created a metamirror that was capable of focusing all of the microwaves to a single point, as is normally done with a parabolic receiver.The team reports that computer simulations showed that the technique could be used to reflect incoming radiation back in virtually any direction and note that such mirrors could find a variety of uses, such as single panels that perform multiple duties, e.g. serving as both a solar collector and radio wave receiver, or a single panel that could route different radio waves from space to different receivers, saving on costs. (Phys.org)—A small team of researchers working at Aalto University in Finland has discovered a way to create “metamirrors” capable of acting on a single radiating frequency while allowing others to pass through. In their paper published in the journal Physical Review Letters, the researchers describe how they embedded metamaterials in certain other materials allowing for the creation of metamirrors with interesting properties. Journal information: Physical Review Letters This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Explore further Citation: Metamaterials used to make metamirrors capable of reflecting one frequency and ignoring all others (2015, March 11) retrieved 18 August 2019 from https://phys.org/news/2015-03-metamaterials-metamirrors-capable-frequency.html © 2015 Phys.org More information: Functional Metamirrors Using Bianisotropic Elements, Phys. Rev. Lett. 114, 095503 – Published 6 March 2015, dx.doi.org/10.1103/PhysRevLett.114.095503 ABSTRACTConventional mirrors obey the simple reflection law that a plane wave is reflected as a plane wave, at the same angle. To engineer spatial distributions of fields reflected from a mirror, one can either shape the reflector or position some phase-correcting elements on top of a mirror surface. Here we show, both theoretically and experimentally, that full-power reflection with general control over the reflected wave phase is possible with a single-layer array of deeply subwavelength inclusions. These proposed artificial surfaces, metamirrors, provide various functions of shaped or nonuniform reflectors without utilizing any mirror. This can be achieved only if the forward and backward scattering of the inclusions in the array can be engineered independently, and we prove that it is possible using electrically and magnetically polarizable inclusions. The proposed subwavelength inclusions possess desired reflecting properties at the operational frequency band, while at other frequencies the array is practically transparent. The metamirror concept leads to a variety of applications over the entire electromagnetic spectrum, such as optically transparent focusing antennas for satellites, multifrequency reflector antennas for radio astronomy, low-profile conformal antennas for telecommunications, and nanoreflectarray antennas for integrated optics.
Share Travelweek Group Posted by Air Namibia appoints Airline Pros as new GSA MONTREAL — Air Namibia (SW) has named Airline Pros its General Sales and Marketing Agent in Canada.“We are excited to represent Namibia’s national flag carrier,” said AirlinePros Canada Director Karl Muller. “We look forward to developing commercial functions for Air Namibia on the Canadian market, strengthening the airline’s brand engagement amongst industry leaders and travellers to increase the number of visitors to the spectacular destination of Namibia.”Air Namibia offers daily overnight flights between Windhoek and Frankfurt on new A3300-200 aircraft. Points in North America, Asia, Middle East and Europe are serviced through partner airlines. Connections bring travellers to Namibia’s Walvis Bay, Luderitz, Lusaka and Oranjemund as well as Cape Town, Durban and Johannesburg in South Africa, Victoria Falls and Harare in Zimbabwe and Gaborone and Maun in Botswana. Visit airlinepros.com/portfolio/air-namibia. Monday, February 6, 2017 << Previous PostNext Post >>