3D printing technology appeared in the mid-1990s and is actually the latest rapid prototyping device using light curing and paper lamination technologies. It is basically the same as ordinary printing. The printer contains liquid or powder and other "printing materials". After connecting to the computer, the "printing materials" are superimposed layer by layer through computer control, and finally the blueprint on the computer is turned into a real object. This printing technology is called 3D printing technology.

• In 1986, American scientist Charles Hull developed the first commercial 3D printing press.

• In 1993, the Massachusetts Institute of Technology was granted a patent for 3D printing technology.

• In 1995, ZCorp of the United States obtained the sole authorization from the Massachusetts Institute of Technology and began to develop a 3D printer.

• In 2005, the first high-definition color 3D printer Spectrum Z510 on the market was successfully developed by ZCorp.

• In November 2010, the American Jim Kor team created the world's first car, Urbee, printed by a 3D printer.

• On June 6, 2011, the world's first 3D printed bikini was released.

• In July 2011, British researchers developed the world's first 3D chocolate printer.

• In August 2011, engineers at the University of Southampton developed the world's first 3D printed aircraft.

• In November 2012, Scottish scientists used human cells to print artificial liver tissue using a 3D printer for the first time.

• In October 2013, the world's first successful auction of a 3D printed artwork named "ONO God".

• In November 2013, SolidConcepts, a 3D printing company based in Austin, Texas, designed and manufactured a 3D printed metal pistol.

• From August 1, 2018, 3D printed guns will be legal in the United States, and the design drawings of 3D printed pistols will also be freely downloadable on the Internet.

• On December 10, 2018, Russian astronauts used a 3D bioprinter on the International Space Station to print out the thyroid gland of a laboratory mouse under zero gravity.

• On January 14, 2019, the University of California, San Diego published a paper in the journal Nature Medicine, using rapid 3D printing technology for the first time to create a spinal cord scaffold that mimics the structure of the central nervous system. It was implanted into the spinal cord after being loaded with neural stem cells. In the damaged spine of the rat, it successfully helped the rat to recover its motor function. The stent is designed to mimic the structure of the central nervous system. It is round with a thickness of only two millimeters. The middle of the stent is an H-shaped structure, surrounded by dozens of tiny channels with a diameter of about 200 microns to guide the implanted neural stem cells and axis. The protrusions grow along the injured spinal cord.

• On April 15, 2019, researchers from Tel Aviv University in Israel used the patient’s own tissues as raw materials to 3D print the world’s first “complete” heart with cells, blood vessels, ventricles and atria. This is the first case in the world (3D printing). heart).

Ordinary printers used in daily life can print flat objects designed by computers. The so-called 3D printers work in the same principle as ordinary printers, except that the printing materials are somewhat different. The printing materials of ordinary printers are ink and paper, and the 3D printer contains metal. Different "printing materials" such as ceramics, plastics, sand, etc. are real raw materials. After the printer is connected to the computer, the "printing materials" can be superimposed layer by layer through computer control, and finally the blueprint on the computer In kind. In layman's terms, a 3D printer is a device that can "print" real 3D objects, such as printing a robot, printing a toy car, printing various models, and even food. The reason why it is commonly called "printer" is based on the technical principles of ordinary printers, because the process of layered processing is very similar to inkjet printing. This printing technology is called 3D stereo printing technology.

There are many different technologies for 3D printing. The difference between them lies in the way the materials are available and the construction of different layers to create parts. Commonly used materials for 3D printing include nylon glass fiber, durable nylon materials, gypsum materials, aluminum materials, titanium alloys, stainless steel, silver-plated, gold-plated, and rubber materials.

Three-dimensional design

The design process of 3D printing is: first modeling by computer modeling software, and then "partitioning" the built 3D model into layer-by-layer sections, that is, slices, so as to instruct the printer to print layer by layer.

The standard file format for collaboration between the design software and the printer is the STL file format. An STL file uses triangles to approximate the surface of an object. The smaller the triangle, the higher the surface resolution. PLY is a scanner for three-dimensional files generated by scanning. The VRML or WRL files generated by it are often used as input files for full-color printing.

Slicing

The printer reads the cross-sectional information in the file, prints these cross-sections layer by layer with liquid, powder or sheet-like materials, and then glues the cross-sections of each layer in various ways to create an entity. The characteristic of this technology is that it can make almost any shape of objects.

The thickness of the section printed by the printer (ie the Z direction) and the resolution in the plane direction that is the X-Y direction are calculated in dpi (pixels per inch) or microns. The general thickness is 100 microns, which is 0.1 mm, and some printers such as ObjetConnex series and 3D Systems' ProJet series can print a thin layer of 16 microns. The plane direction can print out the resolution similar to that of a laser printer. The diameter of the printed "ink drop" is usually 50 to 100 microns. It usually takes several hours to several days to manufacture a model using traditional methods, depending on the size and complexity of the model. The three-dimensional printing technology can shorten the time to several hours, of course, it depends on the performance of the printer and the size and complexity of the model.

Traditional manufacturing technologies such as injection molding can produce polymer products in large quantities at a lower cost, while 3D printing technology can produce relatively small numbers of products in a faster, more flexible, and lower-cost way. A desktop-sized 3D printer can meet the needs of designers or concept development teams to make models.

Finish printing

The resolution of the 3D printer is sufficient for most applications (it may be rough on curved surfaces, like jagged images). To obtain higher resolution items, you can use the following method: first use the current 3D printer Hit a slightly larger object, and then slightly polish the surface to get a smooth "high-resolution" object.

Some technologies can simultaneously use multiple materials for printing. Some technologies also use supports in the printing process. For example, when printing some upside-down objects, you need to use something that is easy to remove (such as soluble matter) as a support.

• Material limitations: Although high-end industrial printing can be printed on plastics, certain metals or ceramics, materials that cannot be printed are relatively expensive and scarce. In addition, the printer has not yet reached a mature level and cannot support the various materials that are exposed in daily life. Researchers have made some progress in multi-material printing, but unless these advances are mature and effective, materials will still be a major obstacle to 3D printing.

• Machine limitations: 3D printing technology has achieved a certain level in reconstructing the geometric shape and function of objects. Almost any static shape can be printed, but those moving objects and their definition are difficult to achieve. This difficulty may be solvable for manufacturers, but if 3D printing technology wants to enter ordinary households, everyone can print what they want at will, so the limitations of the machine must be resolved.

• Intellectual property concerns: In the past few decades, there has been an increasing focus on intellectual property in the music, film and television industries. 3D printing technology will also involve this problem, because many things in reality will be more widely spread. People can copy anything at will, and the number is unlimited. How to formulate 3D printing laws and regulations to protect intellectual property rights is also one of the problems we face, otherwise there will be flooding.

• Moral challenge: Morality is the bottom line. It is difficult to define what kind of things will violate moral laws. If someone prints out biological organs and living tissues, they will encounter great moral challenges in the near future.

• Cost commitment: the cost of 3D printing technology is high. The first 3D printer sold for 15,000. If you want to reach the masses, price reduction is necessary, but it will conflict with cost. Every new technology will face these similar obstacles in the early stage of its birth, but it is believed that finding a reasonable solution 3D printing technology will develop more rapidly, just like any rendering software, it will be constantly updated to achieve the final perfection.