March 25, 2019
When it comes to levitation and propelling objects scientists have seen the light! Physicists have developed a way of achieiving these feats by the power of lightwaves.
Learn about this and more interesting stories from the scientific community in today's issue.
P.S. Did you miss an issue? You can read every issue from the Gophercentral library of newsletters on our exhaustive archives page. Thousands of issues, all of your favorite publications in chronological order. You can read AND comment. Just click
*-- Scientists devise method for levitating, propelling objects with light --*
Physicists at Caltech have developed a method for levitating and propelling objects using only lightwaves. The theoretical feat relies on special nanoscale patterns etched into the surfaces of the light-propelled objects.
Researchers suggest the technology could be used to design light-powered spacecraft capable of visiting planets outside the solar system. The scientists described their theory of light propulsion this week in the journal Nature Photonics.
Physicists have previously used optical tweezers, fine-tuned laser beams, to trap and manipulate nanoparticles. Researchers have also used light to power tiny motors. But scientists have struggled to scale these technologies, which currently only work with very small objects and across very small distances.
"One can levitate a ping pong ball using a steady stream of air from a hair dryer," Ognjen Ilic, postdoctoral researcher at Caltech, said in a news release. "But it wouldn't work if the ping pong ball were too big, or if it were too far away from the hair dryer, and so on."
Ilic and his colleagues claim to have developed a technique for propelling large objects using only light.
Researchers designed special nanoscale surface patterns to interact with the laser beam and reorient the propelled object so that it remains trapped in the stream of photons. The technology doesn't require a highly focused laser beam. As such, the light source can be millions of miles away.
"We have come up with a method that could levitate macroscopic objects," said Harry Atwater, professor of applied physics and materials science at Caltech. "There is an audaciously interesting application to use this technique as a means for propulsion of a new generation of spacecraft. We're a long way from actually doing that, but we are in the process of testing out the principles."
In their paper on the novel theory, the authors suggest spacecraft covered in nanoscale patterns could be propelled by a laser on Earth, freeing it of the need for heavy fuel. The craft could then potentially reach relativistic speeds and visit other stars and planetary systems.
But before the technology is used to accelerate spacecraft, the light propulsion theory could -- according to Atwater -- speed up the manufacturing of tiny objects like circuit boards.
*-- Robots help bees and fish communicate --*
Bees and fish can now converse with each other thanks to new robotics technology designed by researchers in Europe.
Scientists developed robots to translate and deliver signals from groups of bees and schools of fish. The robots traded signals across an international border, allowing bees in Austria to talk to fish a few hundred miles away in Switzerland.
"We created an unprecedented bridge between the two animal communities, enabling them to exchange some of their dynamics," Frank Bonnet, a robotics engineer at the Swiss Federal Institute of Technology in Lausanne, or EPFL, said in a news release.
Previously, researchers at EPFL's Mobile Robots Group have designed and deployed "spy" robots that blend in with groups of animals. Most recently, the team used a robot to infiltrate a school of zebrafish and influence its swimming direction.
For the latest experiment, scientists decided to use the fish spy to help different species communicate.
In Austria, groups of bees naturally swarm around a pair of robot terminals inside a large container. Scientists used the terminals and fish spy to deliver signals and influence the different groups' behavior.
In the experimental hive, the terminals delivered signals in the form of vibrations, temperature variations and air movements. Different signals caused the bees to swarm exclusively around one terminal or the other. Signals from the fish spy caused the school to swim in different directions.
Each robot recorded the movement of the group, and then translated and delivered it to the other robot, which shared the message with the other group.
"The robots acted as if they were negotiators and interpreters in an international conference," said Francesco Mondada, a professor at EPFL's Biorobotics Laboratory. "Through the various information exchanges, the two groups of animals gradually came to a shared decision."
At first, the conversation between the two groups was disorganized, but after 25 minutes, both groups began to synchronize their movements, with the fish swimming exclusively counter clockwise and the bees swarming around a single terminal.
"The species even started adopting some of each other's characteristics. The bees became a little more restless and less likely to swarm together than usual, and the fish started to group together more than they usually would," said Bonnet.
Researchers described the interspecies communication this week in the journal Science Robotics.