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Not all autonomous robots need artificial intelligence to power them. At the molecular level, nanobots can do pretty impressive things without lines of code dictating their moves. They do our bidding because the physical laws of their environment force them to do so.
By exploiting such quirks of nature, scientists have now built nanobots that can repair broken circuits that are too small for a human eye to see. Such tiny repairs could help modern electronics have a longer shelf life, but these proof-of-concept, autonomous nanobots have bigger potential. They could one day soon be used for self-healing materials and delivering drugs inside the human body.
To build them, Joseph Wang of the University of California at San Diego and Anna Balazs of the University of Pittsburgh took inspiration from nature. When you cut yourself, the platelets in your blood sense the wound and start aggregating to start the healing process. They wanted to create tiny robots that could do something similar.
So they started with Janus particles made of gold and platinum. These spherical nanobots (or “nanomotors” as the researchers call them) are thousands of times smaller than a pinhead and have two surfaces with distinct properties. This choice was critical to power the nanobots to act as Wang and Balazs wanted them to.
When these Janus particles are poured in a solution containing hydrogen peroxide, the platinum half of the particles reacts with the chemical, causing oxygen to be released. The reaction is so rapid that the released oxygen propels nanobots like a jet would be propelled by rocket fuel.
To test whether Janus particles in the chemical mixture would do their bidding, Wang and Balazs created a simple circuit that connected a battery to an LED light. Then they broke the circuit by making a scratch that was less than one-tenth the width of a human hair. When Janus particles and hydrogen peroxide solution was poured onto the circuit, the nanobots got into action.
After about 30 minutes, they removed the solution and turned the battery on to find that the LED light was working again. In another broken circuit, simply adding the Janus particles without hydrogen peroxide solution did not lead to repair. The results of the study have been published in the journal Nano Letters.
A computer model of the experiment showed that particles moving randomly could not have repaired the circuit. Instead, Wang and Balazs think that the scratch created differences in the surface energies that the gold-side of the nanobots could “sense.” These energy differences (created by changes in the molecular forces) drove the nanobots to the broken circuit and the geometry of the gap trapped them there.
Next, they are hoping to find new applications for these chemical-powered nanobots. To do that, instead of programming lines of code, they need to find environments where physical laws would dictate the movement of the nanobots. [Reply]
Researchers in Singapore have created cyborg insect using implanted electrodes to control the leg muscles of an African beetle.
In a world first, the researchers show that their system, powered by a 1.5 volt battery, can control the beetle’s step and walking speed.
The researchers at Nanyang Technological University call the cyborg an insect–computer hybrid robot.
The biobot’s eight muscles in its two front legs were electrically stimulated via eight pairs of implanted electrodes, directing the beetle to a gallop.
“We have constructed an insect–computer hybrid legged robot using a living beetle,” the scientists write.
“Different muscles were individually stimulated in a predefined sequence … by a microcontroller. By varying the duration of the stimulation sequences, we successfully controlled the step frequency hence the beetle’s walking speed.
“To the best of our knowledge, this paper presents the first demonstration of living insect locomotion control with a user-adjustable walking gait, step length and walking speed.”
The research is published in the Journal of the Royal Society Interface. [Reply]
A pioneering procedure to regenerate the eye has successfully treated children with cataracts in China. More than half of all cases of blindness are caused by cataracts - the clouding of the eye's lens. An implanted lens is normally needed to restore sight, but the operation described in Nature activated stem cells in the eye to grow a new one. Experts describe the breakthrough as one of the finest achievements in regenerative medicine.
The lens sits just behind the pupil and focuses light on to the retina. About 20 million people are blind because of cataracts, which become more common with age - although some children are born with them. Conventional treatment uses ultrasound to soften and break up the lens, which is then flushed out. An artificial intraocular lens must then be implanted back into the eye, but this can result in complications, particularly in children.
The technique developed by scientists at the Sun Yat-sen University and the University of California, San Diego removes the cloudy cataract from inside the lens via a tiny incision. Crucially it leaves the outer surface - called the lens capsule - intact. This structure is lined with lens epithelial stem cells, which normally repair damage. The scientists hoped that preserving them would regenerate the lens. The team reported that tests on rabbits and monkeys were successful, so the approach was trialled in 12 children.
Within eight months the regenerated lens was back to the same size as normal.
Dr Kang Zhang, one of the researchers, told the BBC News website: "This is the first time an entire lens has been regenerated. The children were operated on in China and they continue to be doing very well with normal vision." It also showed a dramatically lower complication rate "by almost every measure, supporting the superiority of the treatment". However, he says larger trials are needed before it should become the standard treatment for patients.
The procedure was tried in children because their lens epithelial stem cells are more youthful and more able to regenerate than in older patients.
Yet the overwhelming majority of cataracts are in the elderly. Dr Zhang says tests have already started on older pairs of eyes and says the early research "looks very encouraging". Commenting on the findings, Prof Robin Ali from the UCL Institute of Ophthalmology, said the work was "stunning".
He told the BBC News website: "This new approach offers greatly improved prospects for the treatment of paediatric cataracts as it results in regeneration of a normal lens that grows naturally." He said getting similar results in adults "is likely to be more difficult to achieve" but could "have a major impact". "It might be superior to the artificial lenses that are currently implanted, as the natural lenses should be able to accommodate looking at different distances more effectively," he added. Dr Dusko Ilic, a reader in stem cell science at King's College London, said: "The study is one of the finest achievements in the field of regenerative medicine until now.
"It is science at its best."
This is a visuallization of how many Earth's would fit inside the sun....
Volume of the Sun = 1.41*1018 km3
Volume of the Earth = 1.08*1012 km3
Ratio = 1,301,687
Close packing ratio = pi / [3 x sqrt(2)] = 0.74048
1,301,687 x pi / [3 x sqrt(2)] = 963,874 earth volumes in the sun.
And yes, I'm ignoring sig figs here. Sorry. [Reply]
There are just two possible sources in the universe, and neither is on Earth.
Michigan State University researchers, along with colleagues from the Technical University in Darmstadt, Germany, have zeroed in on an answer to one of astronomy’s most perplexing questions: Where did heavy elements, such as gold, come from?
No, your gold ring did not originate from a mine on Earth. Think much, much farther away.
SEE ALSO: The Periodic Table Just Gained Four New Elements
Currently, there are two candidates for where gold came from, neither of which are located on Earth. The first is a supernova, a massive star that when it dies, explodes under its own weight and releases large amounts of heavy elements into space. Second is a neutron-star merger, where two small but massive stars come together and eject huge amounts of stellar debris.
“At this time, no one knows the answer,” Witold Nazarewicz, a professor at the MSU-based Facility for Rare Isotope Beams (FRIB) and one of the co-authors of the paper, said in a press release. “But this work will help guide future experiments and theoretical developments.”
By using existing data, the researchers were able to simulate the production of these heavy elements in both supernovae and neutron-star mergers.
“Our work shows regions of elements where the models provide a good prediction,” Nazarewicz, a Hannah Distinguished Professor of Physics who also serves as FRIB's chief scientist, said in the release. “What we can do is identify the critical areas where future experiments, which will be conducted at FRIB, will work to reduce uncertainties of nuclear models.”
FRIB, which is currently under construction, will allow scientists to make discoveries about the properties of rare isotopes. In doing so, they can gain a better understanding of the physics of nuclei and nuclear astrophysics, and use some of this knowledge for practical societal applications, including medicine and homeland security. [Reply]
SCIENCE KOMBAT ARCADE GAME FEATURING EIGHT SCIENCE LEGENDS IS PLAYABLE NOW
Earlier this month, Brazilian illustrator and game designer Diego Sanches showed sample GIFs of arcade game-style scientists pulling off super sweet science-inspired special moves. The GIFs were teasing characters that were going to be featured in his then-upcoming “newsgame” for Superinteressante magazine. But now, people of reason—and retribution—must wait no longer… for Science Kombat is here!
The game features (please read the following list in the intense tone of the 1992 video game theme song narrator): Charles Darwin… Albert Einstein… Nikola Tesla… Isaac Newton… Stephen Hawking… Pythagoras… Alan Turning… and Marie Curie.
And they are all going to test their might. And their hypotheses.
The game, which can be found here (give it a minute to load), is a classic arcade-style fighter, which uses the D-pad and W and E keys for controls. It’s pretty easy to pick up, and the best part is that all of the scientists’ special moves are based on their respective scientific breakthroughs. Charles Darwin turns into an ape, Einstein leaps through space and time, Stephen Hawking makes black holes appear, Nikola Tesla shoots a huge blast of alternating current, and Alan Turing being the mechano-boss that Alan Turning is, calls in a fleet of flying robots for assistance.
Humans didn't evolve in an environment full of machines, and as a result we have a lot of instinctive reactions to robots that mirror our reactions to other humans. Studies have shown that people have a hard time being rude to a robot's face, just as we do with other people. We even use the same part of our brains to recognize robot and human faces. A research group at Stanford recently wondered if our instinctive reactions to robots would extend to the way we touch their bodies. And they did a series of tests in which subjects were asked to touch robots in "accessible" regions like the hands and then "inaccessible" ones like the buttocks and genitals.
The researchers will present the results of their work this week at the Annual Conference of the International Communication Association in Fukuoka, Japan. They wanted to focus on people's reactions to touch because there is already a large body of evidence showing that humans have complex reactions to touching each other, ranging from emotions to physiological changes we aren't always aware of. As robots take on the roles of caretakers, workplace helpers, and service workers, it's important to explore whether touch should be incorporated into how we design robot interfaces. But first, we need to understand whether humans react to robot touch the way they react to human touch.
To answer that question, the researchers used a human touching scale developed back in the 1960s by Sidney Jourard. Jourard used the term "body accessibility" to rank body parts based on how willing people were to allow others to touch them. As the researchers wrote:
The most accessible regions of the body were the hands, head, and arms while the least accessible region was the genitals. Does the concept of body accessibility extend to robots? If people perceive a robot as simply being a device that can be touched, we would expect no difference in response when touching one part of its body versus another, particularly if its body is of uniform texture and material. If people perceive a robot using a social lens, we would anticipate that touching low accessibility regions would elicit an emotional response associated with greater intimacy between the person and the robot.
The researchers brought study participants into a room with a small humanoid robot (Aldebaran Robotic’s NAO), who was sitting on a table. The robot was programmed to ask participants to touch 12 different parts of its body. Meanwhile, the participants were also wired up to a sensor that tested their skin conductivity. Copious research has already demonstrated that humans' skin becomes more conductive when we're "emotionally aroused." Keep in mind that emotional arousal isn't the same thing as sexual arousal—it simply refers to any strong emotional reaction, from anxiety to desire, that can be measured physiologically.
Not only did study participants have an emotional reaction to touching the robot's inaccessible regions, but they also took fractions of a second longer to touch those parts as well. On an unconscious, instinctual level, humans were reacting to this little humanoid robot as if it were another person. The researchers explain:
These responses are not simply an act of playing along—they occur on a deeper physiological level. People are not inherently built to differentiate between technology and humans. Consequently, primitive responses in human physiology to cues like movement, language, and social intent can be elicited by robots just as they would by real people.
Though there are about a million jokes to be made about this study, the findings are actually quite important. They provide a major insight into UX design for roboticists, especially ones who want to build social robots that will interact with people. Knowing that humans will have unconscious reactions to robots similar to those they have to humans could help in a variety of situations. A gentle touch from a robot could be reassuring. Hugging a robot might trigger physiological reactions that are calming. Touching a robot could also trigger discomfort and even violence.
Jamy Li, one of the researchers who conducted the study, said in a release, "Our work shows that ... people respond to robots in a primitive, social way. Social conventions regarding touching someone else's private parts apply to a robot's body parts as well." This raises the question of what happens when a robot touches a human in an inaccessible body part. Maybe that will mean some robots get a punch in the face. Or they'll be welcomed in a way that hints at the future role of robots in the adult industry.
Reconfigured Tesla coil aligns, electrifies materials from a distance
Scientists at Rice University have discovered that the strong force field emitted by a Tesla coil causes carbon nanotubes to self-assemble into long wires, a phenomenon they call “Teslaphoresis.” The team led by Rice chemist Paul Cherukuri reported its results this week in ACS Nano.
Cherukuri sees this research as setting a clear path toward scalable assembly of nanotubes from the bottom up.
The system works by remotely oscillating positive and negative charges in each nanotube, causing them to chain together into long wires. Cherukuri’s specially designed Tesla coil even generates a tractor beam-like effect as nanotube wires are pulled toward the coil over long distances.
Rice University chemist Paul Cherukuri, left, Texas A&M graduate student Lindsey Bornhoeft, center, and Rice research scientist Carter Kittrell show the power of Teslaphoresis, which wirelessly lights their fluorescent tubes. Tests with a customized Tesla coil revealed that nanotubes within the field self-assemble into wires. Photo by Jeff Fitlow
This force-field effect on matter had never been observed on such a large scale, Cherukuri said, and the phenomenon was unknown to Nikola Tesla, who invented the coil in 1891 with the intention of delivering wireless electrical energy.
“Electric fields have been used to move small objects, but only over ultrashort distances,” Cherukuri said. “With Teslaphoresis, we have the ability to massively scale up force fields to move matter remotely.”
The researchers discovered that the phenomenon simultaneously assembles and powers circuits that harvest energy from the field. In one experiment, nanotubes assembled themselves into wires, formed a circuit connecting two LEDs and then absorbed energy from the Tesla coil’s field to light them.
Cherukuri realized a redesigned Tesla coil could create a powerful force field at distances far greater than anyone imagined. His team observed alignment and movement of the nanotubes several feet away from the coil. “It is such a stunning thing to watch these nanotubes come alive and stitch themselves into wires on the other side of the room,” he said.
Physicists discover flaws in superconductor theory
April 8, 2016
University of Houston physicists report finding major theoretical flaws in the generally accepted understanding of how a superconductor traps and holds a magnetic field. More than 50 years ago, C.P. Bean, a scientist at General Electric, developed a theoretical explanation known as the "Bean Model" or "Critical State Model."
The basic property of superconductors is that they represent zero "resistance" to electrical circuits. In a way, they are the opposite of toasters, which resist electrical currents and thereby convert energy into heat. Superconductors consume zero energy and can store it for a long period of time. Those that store magnetic energy —known as "trapped field magnets" or TFMs—can behave like a magnet.
In the Journal of Applied Physics, the researchers describe experiments whose results exhibited "significant deviations" from those of the Critical State Model. They revealed unexpected new behavior favorable to practical applications, including the possibility of using TFMs in myriad new ways.
Much of modern technology is already based on magnets. "Without magnets, we'd lack generators [electric lights and toasters], motors [municipal water supplies, ship engines], magnetrons [microwave ovens], and much more," said Roy Weinstein, lead author of the study, and professor of physics emeritus and research professor at the University of Houston.
Generally, the performance of a device based on magnets improves as the strength of the magnet increases, up to the square of the increase. In other words, if a magnet is 25 times stronger, the device's performance can range from 25 to 625 times better.
TFMs are clearly intriguing, but their use has been largely held back by the challenge of getting the magnetic field into the superconductor. "A more tractable problem is the need to cool the superconductor to the low temperature at which it superconducts," Weinstein explained.
"Bean assumed the superconductor had zero resistance and that the basic laws of electromagnetism, developed circa 1850, were correct," Weinstein said. "And he was able to predict how and where an external magnetic field would enter a superconductor."
The method widely used today is to apply a magnetic field to a superconductor via a pulse field magnet after the superconductor is cooled. Bean's model predicted, and until now experiments confirmed, that to push as much magnetic field as possible into a superconductor, the pulsed field must be at least twice as strong, and more typically over 3.2 times as strong, as the resulting field of the TFM.
But, this severely limits the applicability of TFMs. "It's difficult and expensive to produce fields of more than 12 tesla," said Weinstein. "If Bean's theory held true, this cost and practicality barrier would limit TFMs used within products to a maximum of typically 3.75 tesla."
Minor problems with Bean's Critical State Model emerged shortly after it was published, according to Weinstein. Any chink in theoretical armor is worthy of an exploratory experiment, and this is what motivated Weinstein and his colleagues.
They discovered that for certain constraints on a magnetic pulse, Bean's model is far off base, and a significantly different spatial distribution of field occurs. "Great increases in field occur suddenly, in a single leap, whereas Bean's model predicts a steady, slow increase," Weinstein said.
All of this new, unexpected behavior is repeatable and controllable. "The most encouraging is that we can now produce full-strength TFMs with a pulse strength 1.0 times that of the TFM," he added.
"By using our newly discovered methods, the maximum TFM field is now 12 tesla," said Weinstein. "A motor, if made in a fixed size, can produce 3.2 times the torque. Alternatively, the motor can be designed to produce the same amount of torque, but have its volume reduced by more than 10 times. This reduction in materials can result in great cost savings."
The researchers are still within the "early days" of this work and have already disproven their first thoughts concerning what is causing their results. "We're now essentially spelunking in a dark cave without lights—it's frustrating, but exciting," Weinstein said.
In terms of applications for their discovery, the researchers suggest the ability to replace a $100,000 low-temperature superconducting magnet in a research X-ray machine with a $300 TFM, or possibly replace a motor with one that is a quarter of the size of an existing one. There are many other potential applications, such as an energy-efficient ore separator, noncontact magnetic gears that will not wear or require repair, a red blood separator with 50 percent improved yield, and even an automated docking system for spacecraft.
Weinstein and colleagues are now searching for fast, short-term support that will allow them to continue their research to explain this new phenomenon. "While we now know enough to apply our new discovery to significantly improve a large number of devices, we don't yet fully know what's going on in terms of the basic laws of physics," he noted. [Reply]
