Multinozzle printer can switch between multiple inks up to 50 times per second
3D printers are revolutionizing manufacturing by allowing users to create any physical shape they can imagine on-demand. However, most commercial printers are only able to build objects from a single material at a time and inkjet printers that are capable of multimaterial printing are constrained by the physics of droplet formation. Extrusion-based 3D printing allows a broad palette of materials to be printed, but the process is extremely slow. For example, it would take roughly 10 days to build a 3D object roughly one liter in volume at the resolution of a human hair and print speed of 10 cm/s using a single-nozzle, single-material printhead. To build the same object in less than 1 day, one would need to implement a printhead with 16 nozzles printing simultaneously!
Now, a new technique called multimaterial multinozzle 3D (MM3D) printing developed at Harvard’s Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences (SEAS) uses high-speed pressure valves to achieve rapid, continuous, and seamless switching between up to eight different printing materials, enabling the creation of complex shapes in a fraction of the time currently required using printheads that range from a single nozzle to large multinozzle arrays. These 3D printheads themselves are manufactured using 3D printing, enabling their rapid customization and facilitating adoption by others in the fabrication community. Each nozzle is capable of switching materials at up to 50 times per second, which is faster than the eye can see, or about as fast as a hummingbird beats its wings. The research is reported in Nature.
“When printing an object using a conventional extrusion-based 3D printer, the time required to print it scales cubically with the length of the object, because the printing nozzle has to move in three dimensions rather than just one,” said co-first author Mark Skylar-Scott, Ph.D., a Research Associate at the Wyss Institute. “MM3D’s combination of multinozzle arrays with the ability to switch between multiple inks rapidly effectively eliminates the time lost to switching printheads and helps get the scaling law down from cubic to linear, so you can print multimaterial, periodic 3D objects much more quickly.”
The key to MM3D printing’s speedy ink-switching is a series of Y-shaped junctions inside the printhead where multiple ink channels come together at a single output nozzle. The shape of the nozzle, printing pressure, and ink viscosity are all precisely calculated and tuned so that when pressure is applied to one of the “arms” of the junction, the ink that flows down through that arm does not cause the static ink in the other arm to flow backwards, which prevents the inks from mixing and preserves the quality of the printed object. By operating the printheads using a bank of fast pneumatic valves, this one-way flow behavior allows the rapid assembly of multimaterial filaments that flow continuously out from each nozzle, and enables the construction of a 3D multimaterial part. The length of the ink channels can also be adjusted to account for materials that have different viscosities and yield stresses, and thus flow more quickly or slowly than other inks.
“Because MM3D printing can produce objects so quickly, one can use reactive materials whose properties change over time, such as epoxies, silicones, polyurethanes, or bio-inks,” said co-first author Jochen Mueller, Ph.D., a Research Fellow at the Wyss Institute and SEAS. “One can also readily integrate materials with disparate properties to create origami-like architectures or soft robots that contain both stiff and flexible elements.”
To demonstrate their technique, the researchers printed a Miura origami structure composed of stiff “panel” sections connected by highly flexible “hinge” sections. Previous methods of building such a structure require manually assembling them together into stacked layers – the MM3D printhead was able to print the entire object in a single step by using eight nozzles to continuously extrude two alternating epoxy inks whose stiffnesses differed by four orders of magnitude after being cured. The hinges withstood over 1,000 folding cycles before failing, indicating the high quality of the transitions between the stiff and flexible materials achieved during printing.
MM3D printing can also be used to create more complex objects, including actuating robots. The research team designed and printed a soft robot composed of rigid and soft elastomers in a millipede-like pattern that included embedded pneumatic channels that enable the soft “muscles” to be compressed sequentially by a vacuum, making the robot “walk.” The robot was able to move at nearly half an inch per second while carrying a load eight times its own weight, and could be connected to other robots to carry heavier loads.
Multimaterial multinozzle 3D (MM3D) printing can switch between up to eight different inks 50 times per second, allowing the creation of complex, high-quality 3D objects in a fraction of the time currently required by other extrusion-based printing methods. Credit: Wyss Institute at Harvard University
“This method enables the rapid design and fabrication of voxelated matter, which is an emerging paradigm in our field,” said corresponding author Jennifer A. Lewis, Sc.D., who is a Core Faculty Member at the Wyss Institute and the Hansjörg Wyss Professor of Biologically Inspired Engineering at SEAS. “Using our broad palette of functional, structural, and biological inks, disparate materials can now be seamlessly integrated into 3D-printed objects on-demand.”
Importantly, current MM3D printheads can only print periodic (i.e., repeating) parts. But the team envisions that MM3D printing will continue to evolve, eventually featuring nozzles that can extrude different inks at different times, smaller nozzles for greater resolution, and even larger arrays for rapid, single-step 3D printing at a wide range of size and resolution scales. They are also exploring the use of sacrificial inks to create even more complex shapes.
“3D printing is revolutionizing the manufacturing industry by allowing people to create without the need for expensive machinery and raw materials, and this new advance promises to dramatically improve the pace of innovation in this exciting area,” said Wyss Founding Director Donald Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and the Vascular Biology Program at Boston Children’s Hospital, as well as Professor of Bioengineering at SEAS.
Learn and see more: Multimaterial 3D printing manufactures complex objects, fast
The Latest on: Multimaterial multinozzle 3D printing
- New Part Dayon March 15, 2020 at 5:00 pm
For decades, we dreamt of a future where all of our electronics used a standardized power connector. Most of us probably didn’t expect that USB would ultimately fill that role, but we’ll take ...
- Search Results for: 2on March 10, 2020 at 5:00 pm
We got an interesting tip this week about a new development in the world of 3D-printing. A group from Harvard demonstrated a multinozzle extruder that can print multimaterial objects in a single pass.
- A new 3D printing technique switches between 'inks' so fast you can’t even see iton March 5, 2020 at 4:00 pm
Mashable is a global, multi-platform media and entertainment company. Powered by its own proprietary technology, Mashable is the go-to source for tech, digital culture and entertainment content ...
- The Year in Review: Bioprinting in 2019on December 12, 2019 at 9:12 pm
Leading bioprinting experts Gordon Wallace, Professor at the University of Wollongong, and Jason Chuen, Vascular Surgeon and Director of the 3D Medical Printing Laboratory in Melbourne ...
via Bing News
The Latest on: 3D printing
- District 218 science teacher wins $10,000 teaching prize, uses money to buy 3D printer for her classroomon March 21, 2020 at 6:10 pm
She now teaches chemistry at Eisenhower High School in Blue Island. The National Science Teachers Association recently honored Caine for the award with a $10,000 prize, which she used to buy a 3D ...
- Hospitals turn to crowdsourcing and 3D printing amid equipment shortageson March 21, 2020 at 5:44 pm
With medical supplies strained by the coronavirus outbreak, health care professionals and technologists are coming together online to crowdsource repairs and supplies of critical hospital equipment.
- 'A worldwide hackathon': Hospitals turn to crowdsourcing and 3D printing amid equipment shortageson March 21, 2020 at 4:05 pm
The efforts come as supply shortages loom in one of the biggest challenges for health care systems around the world.
- Local 3D-printing company creating medical face shieldson March 20, 2020 at 8:25 pm
A local 3D-printing business is hoping to help with the shortage of medical supplies being reported around the country. “This is seemed like a wonderful thing to be able to do,” said Alex Lorenzo.
- 3D Printing As Indirect Patent Infringement Amid COVID-19on March 20, 2020 at 2:39 pm
In Italy, a shortage of vital medical equipment has brought together the worlds of patent law and 3D printing. The equipment, which is apparently patented, is a special valve used in breathing ...
- Grassroots effort to 3D print masks to fight coronavirus is starting in a tiny N.J. shopon March 20, 2020 at 12:00 pm
The Newark resident is part of a new initiative encouraging the 10,000 members of Women in 3D Printing, a global technology organization, to use their hardware and software skills to fight the ...
- 3D Printing in Global Construction: 2019-2027 Market Insights by Printing Method, Material Type, Printing Type, End-user and Regionon March 20, 2020 at 10:15 am
/PRNewswire/ -- The "3D Printing in Construction Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast, 2019 - 2027" report has ...
- Ultimaker Connects 3D Printing Hubs, Experts, and Designers with Hospitals to Enable 3D Printing Support During Coronavirus Outbreakon March 20, 2020 at 9:09 am
/PRNewswire/ -- As countries worldwide face the challenge of managing the COVID-19 pandemic, Ultimaker is making its global network of 3D printing ...
- New York couple 3D-printing 300 face masks for coronavirus testing centeron March 19, 2020 at 11:40 pm
An upstate New York couple is doing their part to protect workers at a coronavirus testing center — by 3D printing 300 protective face masks.
- SmileDirectClub Opens 3D Printing Facility to Provide Coronavirus Medical Supplieson March 19, 2020 at 10:24 pm
SmileDirectClub (NASDAQ:SDC) announced on Thursday that the company is opening a 3D printing facility dedicated to producing much needed COVID-19 medical supplies. The company, which happens to be one ...
via Bing News