Boats 3D printed with new technology Image credit: Dan Congreve
3D printers using lasers can construct an object in any order rather than layer by layer, resulting in more advanced designs than current ones. The paper was recently published in Nature.
Existing 3D printers work by depositing a layer of plastic with a nozzle or curing a layer of resin with ultraviolet light. In both cases, the object is built layer by layer, which means that the overhang of the object must be supported by a temporary bracket until the printing is complete. Then, people carefully remove the bracket manually.
To solve this problem, Dan Congreve and colleagues at Stanford University in the United States invented a 3D printing system that focuses a red laser on a specific point in the resin pool. The resin is filled with 80-nanometer-wide particles that convert red light into blue light once it reaches a certain energy threshold, which only happens at points where the red laser is precisely focused.
When this happens, the surrounding resin will harden against the blue light. This means that individual points in the material can be fixed without the need to cure the resin along the entire beam. This flexibility eliminates the need for layer-by-layer printing, paving the way for more advanced printing.
One or more lasers can rotate around a pool of resin, and when objects are suspended in thick material, they can be printed out in any order, Congreve said. Simply remove the finished product from the remaining resin liquid and rinse. Using existing 3D printers, it is difficult to print out overhang areas and achieve a refined design.
“Because our resin is ‘self-sufficient’ during the printing process, we don’t need any support, which makes post-processing of parts much simpler.” He said.
In addition, Congreve said, “This is a completely new technology.” Because it’s not limited to a layer-by-layer process, we can print traditionally challenging structures, such as cantilevers. ”
The device printed a small boat— an object that is often used as a standard test object for 3D printers, because the boat is small enough and requires fine details such as portholes and open cabin space.
The researchers said, “We have just come into contact with the shallow layers of this new technology. They plan to continue to improve the system to improve printing efficiency and “sculpt” more details. (Source: China Science Daily Wang Fang)
Related paper information:https://doi.org/10.1038/s41586-022-04485-8