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Michael Dickey
เข้าร่วมเมื่อ 27 ก.ย. 2012
Printing Conductive and Transparent Oxide Films at Room Temperature Using Liquid Metal
Paper: "Ambient Printing of Native Oxides for Ultrathin Transparent Flexible Circuit Boards”, Science, 2024.
Researchers have demonstrated a technique for printing thin metal oxide films at room temperature, and have used the technique to create transparent, flexible circuits that are both robust and able to function at high temperatures.
Creating metal oxides that are useful for electronics has traditionally required making use of specialized equipment that is slow, expensive, and operates at high temperatures.
Metal oxides are an important material found in nearly every electronic device. Most metal oxides are electrically insulating (like glass). Metal oxides that are both conductive and transparent are critically important for the touch screen on your smart phone or the monitor on your computer.
In principle, metal oxides are easy to make. They form naturally on the surface of nearly every metal object in our homes - soda cans, stainless steel pots, and forks - yet these oxides are stuck to the surface of the metal.
For this work, the researchers separate the oxide from a meniscus of liquid metal. If you fill a tube with liquid, a meniscus is the curved surface of the liquid that extends beyond the end of the tube. It’s curved because of the surface tension that prevents the liquid from spilling out completely. In the case of liquid metals, the surface of the meniscus is covered with a thin metal oxide skin that forms where the liquid metal meets the air.
The space between two glass slides is filled with liquid metal so that a small meniscus extends beyond the ends of the slides. The slides are the "printer", and the liquid metal is the "ink". The meniscus of liquid metal can then be brought into contact with a surface. The meniscus is covered with oxide on all sides, analogous to the thin rubber that encases a water balloon. Moving the meniscus across the surface, the metal oxide on the front and back of the meniscus sticks to the surface and peels off, like the trail left behind by a snail. As this happens, the exposed liquid on the meniscus constantly forms fresh oxide to enable continuous printing.
The result is that the printer lays down a two-layer thin film of metal oxide that is approximately 4 nm thick.
It works with multiple liquid metals and metal alloys to control the composition of the metal oxide film. It is possible to lay down a stack of layered thin films by making multiple passes with the printer.
One surprising result: the printed films are transparent but have metallic properties. In fact, gold sticks to them. The resulting films are very robust, transparent, and conductive.
Authors: Minsik Kong, Pohang University of Science and Technology and North Carolina State University; Man Hou Vong, Omar Awartani and Michael D. Dickey, North Carolina State University; Mingyu Kwak, Ighyun Lim, Younghyun Lee and Unyong Jeong, Pohang University of Science and Technology; Seong-hun Lee, Jimin Kwon and Tae Joo Shin, Ulsan National Institute of Science and Technology; and Insang You, University of Waterloo
Note: At equilibrium, the oxide that forms on liquid metal is about 3 nm thick. When we print it, we form a bilayer that is 4 nm thick, which means that each layer is less than 3 nm .
Researchers have demonstrated a technique for printing thin metal oxide films at room temperature, and have used the technique to create transparent, flexible circuits that are both robust and able to function at high temperatures.
Creating metal oxides that are useful for electronics has traditionally required making use of specialized equipment that is slow, expensive, and operates at high temperatures.
Metal oxides are an important material found in nearly every electronic device. Most metal oxides are electrically insulating (like glass). Metal oxides that are both conductive and transparent are critically important for the touch screen on your smart phone or the monitor on your computer.
In principle, metal oxides are easy to make. They form naturally on the surface of nearly every metal object in our homes - soda cans, stainless steel pots, and forks - yet these oxides are stuck to the surface of the metal.
For this work, the researchers separate the oxide from a meniscus of liquid metal. If you fill a tube with liquid, a meniscus is the curved surface of the liquid that extends beyond the end of the tube. It’s curved because of the surface tension that prevents the liquid from spilling out completely. In the case of liquid metals, the surface of the meniscus is covered with a thin metal oxide skin that forms where the liquid metal meets the air.
The space between two glass slides is filled with liquid metal so that a small meniscus extends beyond the ends of the slides. The slides are the "printer", and the liquid metal is the "ink". The meniscus of liquid metal can then be brought into contact with a surface. The meniscus is covered with oxide on all sides, analogous to the thin rubber that encases a water balloon. Moving the meniscus across the surface, the metal oxide on the front and back of the meniscus sticks to the surface and peels off, like the trail left behind by a snail. As this happens, the exposed liquid on the meniscus constantly forms fresh oxide to enable continuous printing.
The result is that the printer lays down a two-layer thin film of metal oxide that is approximately 4 nm thick.
It works with multiple liquid metals and metal alloys to control the composition of the metal oxide film. It is possible to lay down a stack of layered thin films by making multiple passes with the printer.
One surprising result: the printed films are transparent but have metallic properties. In fact, gold sticks to them. The resulting films are very robust, transparent, and conductive.
Authors: Minsik Kong, Pohang University of Science and Technology and North Carolina State University; Man Hou Vong, Omar Awartani and Michael D. Dickey, North Carolina State University; Mingyu Kwak, Ighyun Lim, Younghyun Lee and Unyong Jeong, Pohang University of Science and Technology; Seong-hun Lee, Jimin Kwon and Tae Joo Shin, Ulsan National Institute of Science and Technology; and Insang You, University of Waterloo
Note: At equilibrium, the oxide that forms on liquid metal is about 3 nm thick. When we print it, we form a bilayer that is 4 nm thick, which means that each layer is less than 3 nm .
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I wonder how Elon musk would be jealous of this great invention 😂😂
I think it's an important work. But now I am not clear that that what role the liquid metal plays here.
Continuous electro wetting sounds like a dog electro shock collar used to discipline kids who wet the bed! D:
I guess it is not because it acts simply as a ressistor.
Jup, guessed wrong 🤪
So, could we turn a turbine with the liquid and spin a wheel?
Nice. Thanks for the info.
Beside looking awesome, what are some use cases for the metal liquid transfer/grabbing? It's fascinating.
really cool slow acting switches. Immediate use I see is in something that might get temporary jumps in the voltage because of circuit instability but you absolutely must be sure it only triggers intentionally if there's current for a long time.
Powerpoint getting better lol
T-1000 The beginning
Is this a precursor of a future or some slop fed to us underlings to keep us dumb and backward, because, they already walk among us... JCona
O No purpouse engine
If it is mercury, it is a dangerous poison !!
I love your videos Michael. Please keep uploading!
this is so cool. what would be some use cases?
Awesome 🎉
A missed opportunity that they didn't name it Omni-Gel, like from Mass Effect.
it's so beautiful. / space program🦨
Nice! Does the oxidization cause the metal droplet to slowly lose volume over the course of time or is this an indefinitely repeatable proces?
Interesting one shot actuation, but doesn't look reversible. Also, the conductor doesn't need to be gallium, it could be any conductive material, since the operation is electrolysis splitting of water in the hydrogel. Technically any oxygen scavenging material near the positive electrode would result in the same effect.
In that Bubble. what consistency was there inside the bubble Metallic Oxide or Metallic electro gas or Hydrogen what gas it is?
Very cool!
Is it possible that the hydrogel expands when an electric current is placed through it?
Very interesting
Wouldn't the same happen if you bounced a marble off a woofer? ..and you don't even need liquid nitrogen. Sure, a superconductor can be 'charged' to perhaps three to ten tesla instead of a subwoofer's 1.2 or 1.3; but still..
we curse dr scott stanley for the music. UGH
Love it, it’s different. Do not get left behind - Promo>SM!!!
As a material scientist I am always fascinated with these discoveries. Can this ionogel be made DIY ? (if you have the PAA and PAAm). I am guessing the ionic liquid is a common salt solution. So many applications for this material. Great work!
Nice one.
I could see electric vehicles having this installed in the shock suspension system. Every little bump or vibration will send some charge back to the battery extending the total distance it can travel.
One could do that with coils ... no?
@@Gentledutchman That is the train of thought before any new technology is made. Nobody thought wireless charging was possible until a few years ago, same goes for everything else. Its better to be optimistic for future tech.
this is amazing
genius
Each house should have these stretched across the road so as veichle passes it charges a battery in their home.
Then you are just inefficiently converting (stealing) the cars’ energy to the household battery.
@@bjondersson Wouldn't the car battery be losing energy if being driven any way? If driving over a small cable which doesn't need the person to slow down, I don't see how that would effect the car battery capacity. I'm no expert I'm just curious and would love to understand these things better. BTW have you seen those new cars which are able to self charge gaining a 150 mile range a week on sunny days. Pretty damn incredible 😮
@@martin096So where are you suggesting the energy comes from? If you have a small cable that doesn’t seemingly effect the cars speed, then the energy harvested is minimal and probably useless in practice. Better to just put solar cells on the house roof.
@@bjondersson Say for example then someone charged their car from the grid and they need to get from A to B. They will use electric in their vehicle to do that journey any way. Along the way that person drives over a bunch of small cables not really affecting their driving experience which charges up the battery of each home it passes by. The person in the car is happy because they've reached their destination without any problems and the home owners are happy because cars throughout the day have been driving over their cables and charging their battery to use during the evening. We live in a very busy city and get hundreds of cars pass throughout the day, I would love to test that. I suppose it all depends on how much energy you get from cars as they pass by. We are considering solar panels in the next couple years
@@martin096 Energy does not appear from nowhere. You are literally transferring energy from the car to the cables on the road. Your thinking goes wrong when you think that the energy lost from the car is insignificant. You are then transferring an even less insignificant amount of energy to the cable, maybe 10% of that, or less, (rest will be heat). Then you assume that a lot of cars will add up to a significant amount of energy for the harvester. Think about it this way (I'm using imaginary numbers, just as an example): Assume all cars charge at the same charging station. Say that each car charges 10 kWh. A thousand cars will charge 10 000 kWh. That extra bump in the road from the cable will cause friction that makes each car loose 1 mWh. The thousand cars will drive over and cumulatively loose 1 Wh. Out of that you will harvest 0,1 Wh (100 mW). So now you have a system with which a thousand cars have transferred 0,1 Wh to your house from the charging station at the cost of 1 Wh paid by the drivers. For this you have to build a complex harvesting system that will have tear and high maintenance costs. It would be much cheaper and more efficient to just pull that energy directly from the electricity grid than by delivering it by car. Even if you ignore the fact that other drivers are paying your electricity, the maintenance costs would not warrant it. If you still don't get why this is not practical, have a friend in engineering or science explain it to you. I won't try to convince or explain any further.
I wonder if they emptied a fish farm net then filled it up with these and launched a sea dragon out of it how much energy it would re-capture from all that pressure and movement the from the sea dragon launching in water filled with these
liquid metal gallium earth batteries using galfenol nanoparticles
I have been working on liquid metal earth batteries using gallium liquid metal since 2017. ones that can make energy from the microscopic (brownian) motion of water as well as macroscopic movements. this work is VERY similar!
individual units? or would it be a large object scaled up
@@Gerdaldfighterkid ultimately they would be in arrays like the spherical HS-TENG units.
What, what ...??? Do tell !!! Any demonstrations? A TH-cam channel? More info please. Pretty please ...?
@@Gentledutchman th-cam.com/users/peterlang777
Great work!
if you add galfenol nanoparticles to that gallim liquid metal it will be able to convert brownian motion of water not just macroscopic movement. I know because I have worked on this tech since 2017
galfenol is a highly magnetostrictive alloy of iron and gallium developed by the USAF. it is triboelectric and ideal for addition to liquid metal energy harvesters
Hi Prof. Michael Dickey, I have a question. How you manage to guide numerous students in your group? I went to ncsu website and your profile is interesting and make me wanna know how you handle it. I'm really curious, hope you can asnwer the question. TQ
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