” The fantastic thing about surface area stress is that it produces forces that are gentle adequate to grab tiny objects, even with a machine huge enough to fit in your hand.”– Ahmed Sherif
Once in a wide area of the channel, the float would be trapped in the center, kept in location by the repulsive forces in between the walls and float. As the device is lifted out of the water, the repulsive forces change as the shape of the channel modifications. If the float remained in a wide channel to begin, it may discover itself in a narrow channel as the water level falls and need to transfer to the left or right to discover a broader spot.
” The eureka minute came when we found we could move the items by altering the cross-section of our trapping channels,” stated Maya Faaborg, an associate at SEAS and co-first author of the paper.
This basic maker that utilizes the surface area tension of water to grab and manipulate tiny things. Credit: Manoharan Lab/Harvard SEAS
A 3D-printed gadget in a tank of water braids nanowires and relocations microparticles.
New antennae to gain access to higher and greater frequency varieties will be required for the next generation of phones and wireless devices. One method to make antennae that operate at tens of gigahertz– the frequencies needed for 5G and greater gadgets– is to intertwine filaments about 1 micrometer in diameter. Nevertheless, todays industrial fabrication techniques wont work on fibers that small.
” It was a shout-out-loud-in-joy moment when– on our very first try– we crossed 2 fibers using only a piece of plastic, a water tank, and a phase that moves up and down.”– Maya Faaborg
Next, the scientists connected microscopic fibers to the drifts. As the water level altered and the floats moved to the left or right within the channels, the fibers twisted around each other.
” It was a shout-out-loud-in-joy moment when– on our first try– we crossed two fibers using just a piece of plastic, a water tank, and a phase that goes up and down,” said Faaborg.
The team then added a third float with a fiber and created a series of channels to move the floats in an intertwining pattern. They successfully intertwined micrometer-scale fibers of the synthetic product Kevlar. The braid was similar to a traditional three-strand hair braid, other than that each fiber was 10-times smaller sized than a single human hair.
Next, the investigators demonstrated that the floats themselves might be tiny. They constructed machines that might trap and relocation colloidal particles 10 micrometers in size– even though the machines were a thousand times bigger.
” We werent sure it would work, but our estimations revealed that it was possible,” said Ahmed Sherif, a PhD trainee at SEAS and a co-author of the paper. “So we attempted it, and it worked. The remarkable thing about surface stress is that it produces forces that are mild enough to get small items, even with a machine big enough to suit your hand.”
Next, the team intends to design devices that can at the same time manipulate lots of fibers, with the goal of making high-frequency conductors. They likewise plan to develop other makers for micromanufacturing applications, such as building products for optical devices from microspheres.
Reference: “3D-printed makers that control tiny items using capillary forces” by Cheng Zeng, Maya Winters Faaborg, Ahmed Sherif, Martin J. Falk, Rozhin Hajian, Ming Xiao, Kara Hartig, Yohai Bar-Sinai, Michael P. Brenner and Vinothan N. Manoharan, 26 October 2022, Nature.DOI: 10.1038/ s41586-022-05234-7.
The research study was co-authored by Cheng Zeng, Ahmed Sherif, Martin J. Falk, Rozhin Hajian, Ming Xiao, Kara Hartig, Yohai Bar-Sinai and Michael Brenner, the Michael F. Cronin Professor of Applied Mathematics and Applied Physics and Professor of Physics at SEAS. It was supported in part by the Defense Advanced Research Projects Agency (DARPA), under grant FA8650-15-C-7543; the National Science Foundation through the Harvard University Materials Research Science and Engineering Center, under grant DMR-2011754 and ECCS-1541959; and the Office of Naval Research under grant N00014-17-1-3029.
We use a tank of water and a 3D printer, like the ones discovered at lots of public libraries.”
The channel walls are hydrophilic, indicating they bring in water.
As the gadget is lifted out of the water, the repulsive forces alter as the shape of the channel changes. If the float was in a broad channel to begin, it might find itself in a narrow channel as the water level falls and need to move to the left or right to find a wider spot.
The group then added a third float with a fiber and designed a series of channels to move the floats in an intertwining pattern.
Now a team of engineers and researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) has actually developed a simple device that utilizes the surface area stress of water to get and control tiny objects. This impressive development provides a potentially effective tool for nanoscopic production.
The research study was published in the journal Nature on October 26.
” Our work uses a potentially low-cost method to manufacture microstructured and possibly nanostructured materials,” said Vinothan Manoharan, the Wagner Family Professor of Chemical Engineering and Professor of Physics at SEAS and senior author of the paper. “Unlike other micromanipulation approaches, like laser tweezers, our devices can be made quickly. We utilize a tank of water and a 3D printer, like the ones found at many public libraries.”
The machine is a 3D-printed plastic rectangular shape that is about the size of an old Nintendo cartridge. The interior of the device is sculpted with channels that intersect. Each channel has broad and narrow sections, comparable to a river that expands in some parts and narrows in others. The channel walls are hydrophilic, implying they draw in water.
Through a series of experiments and simulations, the researchers discovered that when they immersed the device in water and put a millimeter-sized plastic float in the channel, the surface area tension of the water triggered the wall to drive away the float. If the float remained in a narrow section of the channel, it relocated to a wide section, where it could drift as far away from the walls as possible.
