Soft robots harness viscous fluids for complex motions

Soft Robot
Video Credit: Courtesy of Collective Embodied Intelligence Lab | Cornell University 

One of the virtues of untethered soft robots is their ability to mechanically adapt to their surroundings and tasks, making them ideal for a range of roles, from tightening bolts in a factory to conducting deep-sea exploration. Now they are poised to become even more agile and controlled.

A team of researchers led by Kirstin Petersen, assistant professor of electrical and computer engineering in the College of Engineering, designed a new – and surprisingly simple – system of fluid-driven actuators that enable soft robots to achieve more complex motions. The researchers accomplished this by taking advantage of the very thing – viscosity – that had previously stymied the movement of such robots.

The team’s paper, “Harnessing Nonuniform Pressure Distributions in Soft Robotic Actuators,” published Jan. 20 in Advanced Intelligent Systems. The paper’s lead author is postdoctoral researcher Yoav Matia.

How a 3 cm glass sphere could help scientists understand space weather

UCLA researchers effectively reproduced the type of gravity that exists on or near stars and other planets inside of a glass sphere 3 centimeters in diameter.
Photo Credit: John Koulakis/UCLA 

Solar flares and other types of space weather can wreak havoc with spaceflight and with telecommunications and other types of satellites orbiting the Earth. But, to date, scientists’ ability to research ways to overcome that challenge has been severely limited. That’s because experiments they conduct in laboratories here on Earth are affected by gravity in ways that are so different from conditions in space.

But a new study by UCLA physicists could, at last, help conquer that issue — which could be a big step toward safeguarding humans (and equipment) during space expeditions, and to ensuring the proper functioning of satellites. The paper is published in Physical Review Letters.

The UCLA researchers effectively reproduced the type of gravity that exists on or near stars and other planets inside of a glass sphere measuring 3 centimeters in diameter (about 1.2 inches). To do so, they used sound waves to create a spherical gravitational field and generate plasma convection — a process in which gas cools as it nears the surface of a body and then reheats and rises again as it nears the core — creating a fluid current that in turn generates a magnetic current.

The achievement could help scientists overcome the limiting role of gravity in experiments that are intended to model convection that occurs in stars and other planets.

A soybean protein blocks LDL cholesterol production, reducing risks of metabolic diseases

Graduate student Jennifer Kusumah, center; postdoctoral researcher Erick Damian Castañeda-Reyes, right; and undergraduate student Elen Huang, left; examine the antioxidant effects of soybean proteins that can decrease LDL cholesterol storage in human liver cells, potentially curtailing the development of metabolic diseases such as fatty liver disease and atherosclerosis. 
Photo Credit: Fred Zwicky

A protein in soybeans blocks the production of a liver enzyme involved in the metabolism of triglycerides and low-density lipoprotein, scientists found in a recent study.

Consuming soy flour rich in the protein B-conglycinin has the potential to reduce LDL cholesterol levels and lower the risk of metabolic diseases such as atherosclerosis and fatty liver disease, said Elvira de Mejia, a professor of food science and human nutrition at the University of Illinois Urbana-Champaign and the corresponding author of the study.

Published in the journal Antioxidants, the study was co-written by Neal A. Bringe, a food scientist with Benson Hill Company; and Miguel Rebollo Hernanz, who at the time of the research was a visiting scholar at the U. of I. Rebollo Hernanz is the first author of the paper.

Scientists have long known of soybeans’ cholesterol-lowering properties and lipid-regulating effects, and the current project investigated two soy proteins thought to be responsible for these outcomes – glycinin and B-conglycinin – and found the latter to be particularly significant.

A Rainbow of Force-Activated Pigments

A time-elapse video showing how color develops in areas of a specialized polymer that have been placed under strain.
Video Credit: Peter Holderness/Caltech

Stress isn't just the psychological pressure you feel in response to a looming deadline at work. It is also a description of the physical forces pushing, pulling, or twisting an object, structure, or material. Examples of stress include gravity dragging downward on a bridge, wind blowing against the side of a building, or even a waistband drawn taut by a big meal.

With stress affecting literally everything made and used by people, often in damaging ways, it is important to identify when and where it is happening and the extent to which it is occurring. This is not always easy, though, because many materials show no obvious signs of being under stress.

Caltech's Maxwell Robb, an assistant professor of chemistry, has been working to make stress easier to identify through the creation of polymers that change color when a force is applied to them. Now, in a paper published in Nature Chemistry, Robb shows how his team created a new type of these polymers that can be made to change to almost any colors the user wants. This is in contrast to the polymers he had previously developed, which could only change to a single, predetermined color.

Mutant with Counting Disability

Stimulation of the Venus flytrap by touch triggers electrical signals and calcium waves. The calcium signature is decoded; this causes the trap to shut quickly. The DYSC mutant has lost the ability to read and decode the calcium signature correctly.
Image Credit: Ines Kreuzer / Universität Würzburg

The newly discovered dyscalculia mutant of the Venus flytrap has lost its ability to count electrical impulses. Würzburg researchers reveal the cause of the defect.

The carnivorous Venus flytrap (Dionaea muscipula) can count to five: This discovery by Würzburg biophysicist Professor Rainer Hedrich caused worldwide excitement in 2016. How does the plant count? Hedrich's team from Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, has now described the key component in the journal Current Biology. The researchers found what they were looking for in a mutant of the Venus flytrap that has lost its counting abilities.

Pheasants at risk on unfamiliar ground

Male pheasant
Researchers assessed the performance of 126 captive-reared pheasant chicks on a range of cognitive puzzles
Photo Credit: Jan Temmel

Pheasants are most likely to be killed by predators on unfamiliar ground, according to new research involving the University of Plymouth. 

A new study showed most animals live within a certain area, known as their “home range”, and they know the central areas better than the edges.

To examine how this impacted their outcomes, researchers assessed the performance of 126 captive-reared pheasant chicks on a range of cognitive puzzles. They were then released into the wild and tracked using a high-precision tagging system.

About 40% were killed by predators during the six-month study period – almost all by foxes – and the pheasants were far more likely to die towards the edge of their range.

The findings show this was due to inexperience in these areas, because other birds that knew the same spots well were not likely to die there.

Quantum researchers strike the right chord with silicides

The silicide research team. In the front from left to right: Mark Hersam, Michael Bedzyk, James Ronidnelli and Xiezeng Lu. Back: Carlos Torres and Dominic Goronzy.
Photo Credit: SQMS Center

Just as the sound of a guitar depends on its strings and the materials used for its body, the performance of a quantum computer depends on the composition of its building blocks. Arguably the most critical components are the devices that encode information in quantum computers.

One such device is the transmon qubit — a patterned chip made of metallic niobium layers on top of a substrate, such as silicon. Between the two materials resides an ultrathin layer that contains both niobium and silicon. The compounds of this layer are known as silicides (NbxSiy). Their impact on the performance of transmon qubits has not been well understood — until now.

Silicides form when elemental niobium is deposited onto silicon during the fabrication process of a transmon qubit. They need to be well understood to make devices that reliably and efficiently store quantum information for as long as possible.

Researchers at the Superconducting Quantum Materials and Systems Center, hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory, have discovered how silicides impact the performance of transmon qubits. Their research has been published in APS Physical Review Materials.

A new model for dark matter

This NASA Hubble Space Telescope image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars. Dark matter is an invisible form of matter that accounts for most of the universe’s mass. Hubble cannot see the dark matter directly. Astronomers inferred its location by analyzing the effect of gravitational lensing, where light from galaxies behind Abell 1689 is distorted by intervening matter within the cluster. Researchers used the observed positions of 135 lensed images of 42 background galaxies to calculate the location and amount of dark matter in the cluster. They superimposed a map of these inferred dark matter concentrations, tinted blue, on an image of the cluster taken by Hubble’s Advanced Camera for Surveys. If the cluster’s gravity came only from the visible galaxies, the lensing distortions would be much weaker. The map reveals that the densest concentration of dark matter is in the cluster’s core. Abell 1689 resides 2.2 billion light-years from Earth. The image was taken in June 2002.
Image credit: NASA, ESA, D. Coe (NASA Jet Propulsion Laboratory/California Institute of Technology, and Space Telescope Science Institute), N. Benitez (Institute of Astrophysics of Andalusia, Spain), T. Broadhurst (University of the Basque Country, Spain), and H. Ford (Johns Hopkins University)

Dark matter remains one of the greatest mysteries of modern physics. It is clear that it must exist, because without dark matter, for example, the motion of galaxies cannot be explained. But it has never been possible to detect dark matter in an experiment.

Currently, there are many proposals for new experiments: They aim to detect dark matter directly via its scattering from the constituents of the atomic nuclei of a detection medium, i.e., protons and neutrons.

A team of researchers—Robert McGehee and Aaron Pierce of the University of Michigan and Gilly Elor of Johannes Gutenberg University of Mainz in Germany—has now proposed a new candidate for dark matter: HYPER, or “HighlY Interactive ParticlE Relics.”

Brunt Ice Shelf in Antarctica calves giant iceberg

Chasm-1 remained dormant for many years but has now created a new iceberg.
Photo Credit: British Antarctic Survey

A huge iceberg (1550 km²), almost the size of Greater London, has broken off the 150m thick Brunt Ice Shelf. It calved after cracks that have been developing naturally over the last few years extended across the entire ice shelf, causing the new iceberg to break free. This occurred on Sunday 22 January between 19.00 and 20.00 UTC during spring tide. 

The iceberg calved when the crack known as Chasm-1 fully extended through the ice shelf. The break off is the second major calving from this area in the last two years and has taken place a decade after scientists at British Antarctic Survey (BAS) first detected growth of vast cracks in the ice. 

The Brunt Ice Shelf is the location of BAS Halley Research Station. BAS glaciologists, who have been monitoring the behavior of the ice shelf, say that the area of the ice shelf where the research station is located currently remains unaffected by the recent calving events.  

 The glaciological structure of the Brunt Ice Shelf is complex, and the impact of calving events is unpredictable.  In 2016, BAS took the precaution of relocating Halley Research Station 23 km inland of Chasm-1 after it began to widen.  

New Tool Uses Ultrasound ‘Tornado’ to Break Down Blood Clots

Ultrasonic Tornado
Illustration Credit: Xiaoning Jiang / Courtesy of North Carolina State University

Researchers have developed a new tool and technique that uses “vortex ultrasound” – a sort of ultrasonic tornado – to break down blood clots in the brain. The new approach worked more quickly than existing techniques to eliminate clots formed in an in vitro model of cerebral venous sinus thrombosis (CVST).

“Our previous work looked at various techniques that use ultrasound to eliminate blood clots using what are essentially forward-facing waves,” says Xiaoning Jiang, co-corresponding author of a paper on the work. “Our new work uses vortex ultrasound, where the ultrasound waves have a helical wavefront.

“In other words, the ultrasound is swirling as it moves forward,” says Jiang, who is the Dean F. Duncan Professor of Mechanical and Aerospace Engineering at North Carolina State University. “Based on our in vitro testing, this approach eliminates blood clots more quickly than existing techniques, largely because of the shear stress induced by the vortex wave.”

“The fact that our new technique works quickly is important, because CVST clots increase pressure on blood vessels in the brain,” says Chengzhi Shi, co-corresponding author of the work and an assistant professor of mechanical engineering at Georgia Tech. “This increases the risk of a hemorrhage in the brain, which can be catastrophic for patients.