Revolutionary 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, 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.”
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.
Jam sessions: making magnets out of liquids
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 by 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.
Learn and see more: New Laws of Attraction: Scientists Print Magnetic Liquid Droplets
The Latest on: 3D-printable magnetic liquid devices
[google_news title=”” keyword=”3D-printable magnetic liquid devices” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: 3D-printable magnetic liquid devices
- Engineering Newson April 22, 2024 at 4:59 pm
An Ink for 3D-Printing Flexible Devices Without Mechanical Joints Apr. 18, 2024 — Researchers are targeting the next generation of soft actuators and robots with an elastomer-based ink for 3D ...
- Elastomer-based ink to 3D-print flexible devices without mechanical jointson April 20, 2024 at 12:41 pm
Researchers reveal 3D-printable elastomers with variable stiffness, enabling lightweight yet functional soft robotics and wearable devices.
- An ink for 3D-printing flexible devices without mechanical jointson April 18, 2024 at 6:01 am
For engineers working on soft robotics or wearable devices, keeping things light ... To overcome this problem, we developed DNGEs: 3D-printable double network granular elastomers that can vary ...
- An ink for 3D-printing flexible devices without mechanical jointson April 17, 2024 at 5:00 pm
Researchers are targeting the next generation of soft actuators and robots with an elastomer-based ink for 3D printing objects ... on soft robotics or wearable devices, keeping things light ...
- Researchers 3D print key components for a point-of-care mass spectrometeron April 7, 2024 at 5:00 pm
He and his collaborators have taken a big step in that direction by 3D printing a low-cost ionizer ... to strategically restrict the flow of liquid. Pictured are some photos and illustrations of the ...
- Researchers 3D print key components for a point-of-care mass spectrometeron April 4, 2024 at 7:42 am
By 3D printing the device instead, the researchers were able ... an ionizer is used to give them a charge before they are analyzed. Most liquid ionizers do this using electrospray, which involves ...
- Cool Things To 3D Print That You've Probably Never Thought To Tryon February 19, 2024 at 7:47 am
3D printing is a downright futuristic ... Julien Coyne of Mojoptix designed a digital sundial you can print on your own. This unique device displays digital numbers on the ground in the form ...
- 3D-Printed Rockets Set To Blast Offon June 30, 2022 at 9:31 am
Chipping millions off the cost of deploying satellites recently garnered Launcher funding from the U.S. Space Force to further develop its E-2 3D-printed, high-performance liquid rocket engine for ...
- 3D Printed Maglev Switches Are So Hot Right Nowon February 8, 2022 at 6:05 am
Thanks to this phenomenon we’re happy to report that yet another 3D printable magnetic ... With these two magnetic mavens collaborating, the future of bespoke input devices is looking very ...
- 3D printable 2D materials based inks show promise to improve energy storage deviceson August 17, 2020 at 2:36 am
For the first time, a team of researchers, from the Department of Materials and the National Graphene Institute at The University of Manchester have formulated inks using the 2D material MXene, to ...
via Bing News