DOE News
    Doe Science news source
    The DOE Science News Source is a Newswise initiative to promote research news from the Office of Science of the DOE to the public and news media.
    • 2019-07-17 05:05:29
    • Article ID: 715925

    New Laws of Attraction: Scientists Print Magnetic Liquid Droplets

    Amazing magnetic, liquid material could lead to 3D-printable magnetic liquid devices for the fabrication of flexible electronics, or artificial cells that deliver targeted drug therapies to diseased cells

    Inventors of centuries past and scientists of today have found ingenious ways to make our lives better with magnets – from the magnetic needle on a compass to magnetic data storage devices and even MRI body scan machines.

    All of these technologies rely on magnets made from solid materials. But what if you could make a magnetic device out of liquids? Using a modified 3D printer, a team of scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have done just that. Their findings, to be published July 19 in the journal Science (DOI: 10.1126/science.aaw8719), could lead to a revolutionary class of printable liquid devices for a variety of applications – from artificial cells that deliver targeted cancer therapies to flexible liquid robots that can change their shape to adapt to their surroundings.  

    “We’ve made a new material that is both liquid and magnetic. No one has ever observed this before,” said Tom Russell, a visiting faculty scientist at Berkeley Lab and professor of polymer science and engineering at the University of Massachusetts, Amherst, who led the study. “This opens the door to a new area of science in magnetic soft matter.”

    Jam sessions: making magnets out of liquids

    For the past seven years, Russell, who leads a program called Adaptive Interfacial Assemblies Towards Structuring Liquids in Berkeley Lab’s Materials Sciences Division and also led the current study, has focused on developing a new class of materials – 3D-printable all-liquid structures.

    Russell and Xubo Liu, the study’s lead author, came up with the idea of forming liquid structures from ferrofluids, which are solutions of iron-oxide particles that become strongly magnetic in the presence of another magnet. “We wondered, ‘If a ferrofluid can become temporarily magnetic, what could we do to make it permanently magnetic, and behave like a solid magnet but still look and feel like a liquid?’” said Russell.

    To find out, Russell and Liu used a 3D-printing technique they had developed with former postdoctoral researcher Joe Forth in Berkeley Lab’s Materials Sciences Division to print 1 millimeter droplets from a ferrofluid solution containing iron-oxide nanoparticles just 20 nanometers in diameter (the average size of an antibody protein).

    Using surface chemistry and sophisticated atomic force microscopy techniques, staff scientists Paul Ashby and Brett Helms of Berkeley Lab’s Molecular Foundry revealed that the nanoparticles formed a solid-like shell at the interface between the two liquids through a phenomenon called “interfacial jamming.” This causes the nanoparticles to crowd at the droplet’s surface, “like the walls coming together in a small room jampacked with people,” said Russell. 

    To make them magnetic, the scientists placed the droplets using a magnetic coil in solution. As expected, the magnetic coil pulled the iron-oxide nanoparticles toward it.   

    But when they removed the magnetic coil, something quite unexpected happened.

    Like synchronized swimmers, the droplets gravitated toward each other in perfect unison, forming an elegant swirl “like little dancing droplets,” said Liu, who is a graduate student researcher in Berkeley Lab’s Materials Sciences Division and a doctoral student at the Beijing University of Chemical Technology.   

    Somehow, these droplets had become permanently magnetic. “We almost couldn’t believe it,” said Russell. “Before our study, people always assumed that permanent magnets could only be made from solids.” 

    Measure by measure, it’s still a magnet  

    All magnets, no matter how big or small, have a north pole and a south pole. Opposite poles are attracted to each other, while the same poles repel each other. 

    Through magnetometry measurements, the scientists found that when they placed a magnetic field by a droplet, all of the nanoparticles’ north-south poles, from the 70 billion iron-oxide nanoparticles floating around in the droplet to the 1 billion nanoparticles on the droplet’s surface, responded in unison, just like a solid magnet.

    Key to this finding were the iron-oxide nanoparticles jamming tightly together at the droplet’s surface. With just 8 nanometers between each of the billion nanoparticles, together they created a solid surface around each liquid droplet.

    Somehow, when the jammed nanoparticles on the surface are magnetized, they transfer this magnetic orientation to the particles swimming around in the core, and the entire droplet becomes permanently magnetic – just like a solid, Russell and Liu explained.  

    The researchers also found that the droplet’s magnetic properties were preserved even if they divided a droplet into smaller, thinner droplets about the size of a human hair, added Russell.

    Among the magnetic droplets’ many amazing qualities, what stands out even more, Russell noted, is that they change shape to adapt to their surroundings. They morph from a sphere to a cylinder to a pancake, or a tube as thin as a strand of hair, or even to the shape of an octopus – all without losing their magnetic properties.

    The droplets’ can also be tuned to switch between a magnetic mode and a nonmagnetic mode. And when their magnetic mode is switched on, their movements can be remotely controlled as directed by an external magnet, Russell added.

    Liu and Russell plan to continue research at Berkeley Lab and other national labs to develop even more complex 3D-printed magnetic liquid structures, such as a liquid-printed artificial cell, or miniature robotics that move like a tiny propeller for noninvasive yet targeted delivery of drug therapies to diseased cells.

    “What began as a curious observation ended up opening a new area of science,” said Liu. “It’s something all young researchers dream of, and I was lucky to have the chance to work with a great group of scientists supported by Berkeley Lab’s world-class user facilities to make it a reality,” said Liu.

    Also contributing to the study were researchers from UC Santa Cruz, UC Berkeley, the WPI–Advanced Institute for Materials Research (WPI-AIMR) at Tohoku University, and Beijing University of Chemical Technology.

    The magnetometry measurements were taken with assistance from co-authors Peter Fischer, senior staff scientist in Berkeley Lab’s Materials Sciences Division; Frances Hellman, senior faculty scientist at Berkeley Lab and professor of physics at UC Berkeley; Robert Streubel, Berkeley Lab postdoctoral fellow; Noah Kent, Berkeley Lab graduate student researcher and doctoral student at UC Santa Cruz; and Alejandro Ceballos, Berkeley Lab graduate student researcher and doctoral student at UC Berkeley.

    Other co-authors are staff scientists Paul Ashby and Brett Helms, and postdoctoral researchers Yu Chai and Paul Kim, with Berkeley Lab’s Molecular Foundry; Yufeng Jiang, graduate student researcher in Berkeley Lab’s Materials Sciences Division; and Shaowei Shi and Dong Wang of Beijing University of Chemical Technology.  

    This work was supported by the DOE Office of Science and included research at the Molecular Foundry, a DOE Office of Science User Facility that specializes in nanoscale science. 

    For more information about technologies developed under the Adaptive Interfacial Assemblies Towards Structuring Liquids at Berkeley Lab, see:

     

    ###

    Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory and its scientists have been recognized with 13 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy's Office of Science. 

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

     

    • other-fb
    • other-tw
    X
    X
    X
    • Filters

    • × Clear Filters
    Study shows a much cheaper catalyst can generate hydrogen in a commercial device

    Study shows a much cheaper catalyst can generate hydrogen in a commercial device

    SLAC and Stanford researchers have shown for the first time that a cheap catalyst can split water and generate hydrogen gas for hours on end in the harsh environment of a commercial electrolyzer - a step toward large-scale hydrogen production for fuel, fertilizer and industry.

    Unlocking the Biochemical Treasure Chest Within Microbes

    Unlocking the Biochemical Treasure Chest Within Microbes

    An international team of scientists lead by the Joint Genome Institute has developed a genetic engineering tool that makes producing and analyzing microbial secondary metabolites - the basis for many important agricultural, industrial, and medical products - much easier than before, and could even lead to breakthroughs in biomanufacturing.

    Scientists Pinpoint Cause of Harmful Dendrites and Whiskers in Lithium Batteries

    Scientists Pinpoint Cause of Harmful Dendrites and Whiskers in Lithium Batteries

    Scientists have uncovered a root cause of the growth of needle-like structures--known as dendrites and whiskers--that plague lithium batteries, sometimes causing a short circuit or failure. The defects are a major factor holding back the batteries from broader widespread use and further improvement.

    Argonne and University of Illinois to form hydrogen fuel cell coalition

    Argonne and University of Illinois to form hydrogen fuel cell coalition

    Argonne and University of Illinois announce intent to form the Midwest Hydrogen and Fuel Cell Coalition.

    Six Degrees of Nuclear Separation

    Six Degrees of Nuclear Separation

    For the first time, Argonne scientists have printed 3D parts that pave the way to recycling up to 97 percent of the waste produced by nuclear reactors. From left to right: Peter Kozak, Andrew Breshears, M Alex Brown, co-authors of a recent Scientific Reports article detailing their breakthrough. (Image by Argonne National Laboratory.)

    Shaping nanoparticles for improved quantum information technology

    Shaping nanoparticles for improved quantum information technology

    Argonne researchers find that semiconductor nanoparticles in the shape of rings have attractive properties for quantum networking and computation.

    Science Snapshots - Waste to fuel, moire superlattices, mining cellphones for energy data

    Science Snapshots - Waste to fuel, moire superlattices, mining cellphones for energy data

    Science Snapshots - Waste to fuel, moire superlattices, mining cellphones for energy data

    New Electrolyte Stops Rapid Performance Decline of Next-Generation Lithium Battery

    New Electrolyte Stops Rapid Performance Decline of Next-Generation Lithium Battery

    Researchers at Argonne National Laboratory have designed and tested a new electrolyte composition that could greatly accelerate the adoption of the next generation of lithium-ion batteries.

    Light My Fire: How to Startup Fusion Devices Every Time

    Light My Fire: How to Startup Fusion Devices Every Time

    Researchers have constructed a framework for starting and raising a fusion plasma to temperatures rivaling the sun in hundreds of milliseconds.

    Atomic-level Imaging Could Offer Roadmap to Metals with New Properties

    Atomic-level Imaging Could Offer Roadmap to Metals with New Properties

    A team of researchers at the Georgia Institute of Technology has developed a new process that could help gain new insights into individual high-entropy alloys and help characterize their properties.


    • Filters

    • × Clear Filters
    Barbara Jacak Receives 2019 Distinguished Scientist Fellow Award

    Barbara Jacak Receives 2019 Distinguished Scientist Fellow Award

    Barbara Jacak, director of Lawrence Berkeley National Laboratory's Nuclear Science Division since 2015, has been named a 2019 Distinguished Scientist Fellow by the U.S. Department of Energy's Office of Science.

    Two Brookhaven Lab Scientists Named DOE Office of Science Distinguished Fellows

    Two Brookhaven Lab Scientists Named DOE Office of Science Distinguished Fellows

    Scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have garnered two out of five "Distinguished Scientists Fellow" awards announced today by the DOE's Office of Science. Theoretical physicist Sally Dawson, a world-leader in calculations aimed at describing the properties of the Higgs boson, and Jose Rodriguez, a renowned chemist exploring and developing catalysts for energy-related reactions, will each receive $1 million in funding over three years to pursue new research objectives within their respective fields.

    Department of Energy Announces Private-Public Awards to Advance Fusion Energy Technology

    The U.S. Department of Energy (DOE) announced funding for 12 projects with private industry to enable collaboration with DOE national laboratories on overcoming challenges in fusion energy development. The awards are the first provided through the Innovation Network for Fusion Energy program (INFUSE).

    Denisov Leads High Energy Physics at Brookhaven

    Denisov Leads High Energy Physics at Brookhaven

    Dmitri Denisov, a leading physicist and spokesperson of the DZero experiment, has been named Deputy Associate Lab Director for High Energy Physics at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory.

    Chemistry Postdoc Receives Battery500 Young Investigator Award

    Chemistry Postdoc Receives Battery500 Young Investigator Award

    Zulipiya Shadike, a postdoctoral fellow in the Chemistry Division at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, received a Young Investigator Award from the Battery500 Consortium, a DOE-sponsored consortium led by Pacific Northwest National Laboratory (PNNL) that aims to improve electric vehicle batteries.

    Two Brookhaven Lab Scientists Named Fellows of the American Physical Society

    Two Brookhaven Lab Scientists Named Fellows of the American Physical Society

    The American Physical Society (APS) has elected two scientists from Brookhaven National Laboratory as 2019 APS fellows.

    Versatile physics leader Stefan Gerhardt elected an APS fellow

    Versatile physics leader Stefan Gerhardt elected an APS fellow

    Profile of physicist Stefan Gerhardt who has been elected a 2019 fellow of the American Physical Society.

    PNNL, Sandia, and Georgia Tech Join Forces in AI Effort

    PNNL, Sandia, and Georgia Tech Join Forces in AI Effort

    Scientists from DOE's Pacific Northwest National Laboratory, DOE's Sandia National Laboratories, and the Georgia Institute of Technology will collaborate on solutions to some of the most challenging problems in AI today, thanks to $5.5 million in funding from DOE.

    Argonne Receives More Than $1 Million for Quantum Information Science

    Argonne Receives More Than $1 Million for Quantum Information Science

    Argonne scientists receive $1.19 million from DOE for quantum research.

    Department of Energy Announces $6.6 Million to Study Dark Matter

    The U.S. Department of Energy (DOE) announced $6.6 million for four new research awards to develop design concepts for dark matter search experiments.


    • Filters

    • × Clear Filters
    Tracing Interstellar Dust Back to the Solar System's Formation

    Tracing Interstellar Dust Back to the Solar System's Formation

    This study is the first to confirm dust particles pre-dating the formation of our solar system. Further study of these materials will enable a deeper understanding of the processes that formed and have since altered them.

    Investigating Materials that Can Go the Distance in Fusion Reactors

    Investigating Materials that Can Go the Distance in Fusion Reactors

    Future fusion reactors will require materials that can withstand extreme operating conditions, including being bombarded by high-energy neutrons at high temperatures. Scientists recently irradiated titanium diboride (TiB2) in the High Flux Isotope Reactor (HFIR) to better understand the effects of fusion neutrons on performance.

    Better 3-D Imaging of Tumors in the Breast with Less Radiation

    Better 3-D Imaging of Tumors in the Breast with Less Radiation

    In breast cancer screening, an imaging technique based on nuclear medicine is currently being used as a successful secondary screening tool alongside mammography to improve the accuracy of the diagnosis. Now, a team is hoping to improve this imaging technique.

    Microbes are Metabolic Specialists

    Microbes are Metabolic Specialists

    Scientists can use genetic information to measure if microbes in the environment can perform specific ecological roles. Researchers recently analyzed the genomes of over 6,000 microbial species.

    Even Hard Materials Have Soft Spots

    Even Hard Materials Have Soft Spots

    The Achilles Heel of "metallic glasses" is that while they are strong materials--even stronger than conventional steels--they are also very brittle. The initial failures tend to be localized and catastrophic. This is due to their random amorphous (versus ordered crystalline) atomic structure. Computer simulations revealed that the structure is not completely random, however, and that there are some regions in the structure that are relatively weak. Defects nucleate more easily in these regions, which can lead to failure. This understanding of the mechanical properties has led to a strategy for making the material stronger and less brittle.

    2-D Atoms Do the Twist

    2-D Atoms Do the Twist

    In the study, scientists demonstrated, for the first time, an intrinsically rotating form of motion for the atoms in a crystal. The observations were on collective excitations of a single molecular layer of tungsten diselenide. Whether the rotation is clockwise or counter-clockwise depends on the wave's propagation direction.

    Location, Location, Location... How charge placement can control a self-assembled structure

    Location, Location, Location... How charge placement can control a self-assembled structure

    For years, scientists have formed polymers using the interaction of charges on molecular chains to determine the shape, geometry, and other properties. Now, a team achieved precise and predictable control of molecular chains by positioning charges. Their method leads to particles with reproducible sizes.

    Cracking in Harsh Environments Needs Stress and Corrosion, But Not at the Same Time

    Cracking in Harsh Environments Needs Stress and Corrosion, But Not at the Same Time

    Alloys (metals combining two or more metallic elements) are typically stronger and less susceptible to cracking than pure metals. Yet when alloys are subjected to stress and a harsh chemical environment, the alloy can fail. The reason? Cracks caused by corrosion.

    Simultaneous Clean and Repair

    Simultaneous Clean and Repair

    Scientists have developed a novel and efficient approach to surface cleaning, materials transport, and repair.

    Where Does Salt in the Amazon Air Come From?

    Where Does Salt in the Amazon Air Come From?

    Tiny particles of sodium salt float in the air over the pristine Amazon basin. Why? The only explanation before now has been that winds blow marine particles hundreds of miles inland from the Atlantic Ocean. An international team of scientists used chemical imaging and atmospheric models to prove otherwise.


    Spotlight





    Showing results

    0-4 Of 2215