This article is from WeChat public account: China Science Popularization Expo (ID: kepubolan) , produced by Science China, Production: Osaka University, Producer: Computer Network Information Center, Chinese Academy of Sciences
With the continuous spread of the new crown epidemic in the world, a number of severely affected areas, including the United States and Italy, have experienced shortages of health and medical supplies, masks, ventilators, and nasal and throat swabs for testing. Essential supplies are in short supply.
In critical times, 3D printing technology has become a life-saver. Last week, a coalition of institutions including the University of South Florida, Harvard University, and Stanford University announced that they had signed a FDA) consultations to develop general guidelines for the production of 3D printed test samples. Meanwhile, Formlabs, a developer and manufacturer of 3D printing technology based in Somerville, Mass., Will invest 250 printers in its Ohio plant to produce nasal swabs for the New Coronavirus test.
3D printed nasal swabs for new crown virus test Image source: Formlabs
In fact, 3D printing has also contributed to China’s fight against the new crown epidemic . onA technology company in Hainan applied 3D printing technology to “print” isolated wards to help Hubei. A group in Hunan produced a batch of medical goggles to help fight the epidemic with 3D technology. Its weight is only three quarters of that of ordinary goggles. At the same time, it can be customized according to personal facial data.
Isolation ward “printed” by 3D technology Picture source: Chinanews.com
The rapid development of 3D printing technology makes people wonder: what is magical 3D printing that you can’t do?
Part.1 3D printing has been born for a long time
3D printing is not new, its predecessor was Rapid Prototyping , and it has been used in industrial design and production processes in the 1980s. Basically, the 3D printing technologies that are commonly used at the time were basically developed. Instead, the name 3D printing came late, and it wasn’t until 1995 that two MIT graduates JimBredt and TimAnderson came up with the concept of “3D printing” for the first time.
Although there are many 3D printing technologies, the ideas are the same, and the technical term is “ Distributed Material Manufacturing “. Take an example that is easy for everyone to understand: it takes a long time for a person to make a cabinet. If you want to speed up, you need to increase the number of people. But if there is a fixed number of people, how can you speed up the manufacturing speed? That is to make a stack of wood, and then find someone to stack the bricks in a certain shape, and then stick it-as long as he can understand the instructions.
Image Source: Veer Gallery
Part.2 3D printing is unique
Compared with traditional processing methods, 3D printing has many unique features.
First, it takes a few steps to produce a small car part by the traditional stamping method. First, a stamping die is required. This mold is like the moon cake print, which determines the shape of the part. Generally made of special mold steel, high hardness and good toughness. The mold is divided into an upper mold and a lower mold. The upper mold is installed on the press, and can be pressed into the lower mold at a high speed. The material to be processed is like the dough for making moon cakes. After being pressed in such an instant, it becomes the shape of a mold. After that, the extra parts are removed by a lathe, and then some machining such as grinding and polishing is performed, and the parts are completed.
Small automotive parts made by stamping process (Credit: Nagoya Toyota Museum Memorial)
What is the routine for 3D printing the same parts? First, draw the design drawing of the part on your computer, then import the design data into a 3D printer, and you can start manufacturing the part.
Take a fused deposition type 3D printer as an example. Low-melting-point wires such as plastic and paraffin prepared in advance are heated and sprayed through the nozzle of the 3D printer. Under the control of the computer, the nozzles are drawn layer by layer in the space from low to high, and finally form parts, basicNo post processing is required.
Left: A plastic fused deposition type low-end industrial 3D printer, the white coil is the plastic material
Right: Close-up of the nozzle part of the printer, dual nozzle design, can print two different plastics at the same time Image source: Baidu Pictures
The above example has clearly reflected the two most essential features of 3D printing. First, 3D printing and computer-aided design (CAD) and computer-aided manufacturing (CAM) Inseparable , any 3D printed part must start its own life course from computer design drawings. If only the drawings are available in advance, there is no modeling data that can be directly used by the computer, and the model must be rebuilt in the computer and the design drawings drawn.
Second, 3D printing is an additive manufacturing technology , that is to say, unlike traditional lathe machining and other subtractive manufacturing technologies, products are directly stacked in space from raw materials. . The machining of a lathe can be compared to stone carving, and the knife and axe go into battle. The final work is no less than the original rough.
On the other hand, 3D printing is like clay sculpture. The components that shape the image are constantly superimposed. The final work is only a lot more than the original clay embryo. With these two characteristics that are very different from other predecessors, it is not surprising that 3D printing can stand alone in the martial arts of mechanical manufacturing technology.
Part.3 3D printingTechnology, biological materials can also be printed out
After the birth of 3D printing technology, people invented 3D bioprinting in order to solve the problem of limited source of transplanted organs. Because in the existing medical methods, the acquisition of one organ is based on the loss of another human organ, and the number of organs that are actively or passively lost is far less than the required organs. 3D bioprinters based on existing printing technologies use biomaterials, which can compound active ingredients such as cells and growth factors to build living tissue layer by layer.
3D bioprinting process (Image source: Baidu picture)
Organovo produced the first prototype of a 3D bioprinter at the end of 2009. Researchers combined stem cells extracted from bone marrow, fat, and other tissues in the liquid material for printing, or different active factors, and printed the liquid on the receiving platform according to a certain pattern through the print head. Each time the print head prints a layer, it will raise the scale of a layer height, and then start the printing of the next layer pattern, so as to gradually realize the formation of artificial tissue, this process is similar to the ordinary 3D printing model manufacturing in industrial applications.
3D printing is also widely used in other biological fields.
3D printing technology has been widely used in medical titanium alloy artificial bones and artificial joints. First, the precise three-dimensional structure of the patient’s body is known through imaging techniques such as CT or nuclear magnetic resonance, and then the data is processed using a computer and a personalized design is completed. Later, 3D printing was used to generate unique and exclusive artificial bones, which greatly improved the quality of treatment for patients.
In 2017, a team from Northwestern University used 3D printing technology to print gelatin into a structure similar to ovarian tissue. Follicles and hormone-producing cells extracted from mice were then implanted into this gelatin skeleton to obtain 3D printed artificial ovarian tissue. After the artificial ovary was transplanted into the ovary-removed mouse, it showed the characteristics of a functional ovary, and it could ovulate normally.There were no abnormalities in offspring after many generations of reproduction.
Scientists hold a gel-like mouse ovarian bioprosthesis with tweezers. Image source: Yangguang.com
Although it is still far from the ultimate human dream of artificially making tissues or organs, 3D printing has helped us take a pioneering step.
3D printing can be expected in the future.
This article is from WeChat public account: China Science Popularization Expo (ID: kepubolan) , produced by Popular Science China, produced by Osaka University, produced by Computer Network Information Center of Chinese Academy of Sciences