Science's revolutionary "volume 3D printing technology" is questioned by plagiarizing a patent that Chinese Beijinger Wu Xiang applied for in 2015

Science's revolutionary "volume 3D printing technology" prints a portrait for dozens of seconds and is questioned by plagiarizing a patent that Chinese Beijinger Wu Xiang applied for in 2015. Wu Xiang believes that the patent transfer value is $15.1 billion!

Recently, the world's top academic journal "Science" published a revolutionary "Volumetric additive manufacturing via tomographic reconstruction" (PDF), which can print a complete portrait in tens of seconds.

△ First, put a photosensitive resin liquid material in a cup, use DLP light source for body exposure, turn the cup to rotate, and cure the resin at the specified position.

△ works like a reverse computed tomography (CT) scan. In a CT machine, an X-ray tube rotates around the patient to take a picture of the internal organs of the human body. The computer then reconstructs a 3D picture using these projections. In the case of a computer simulating a 3D object, the researchers calculate the shape of the object from a number of different angles and then input the resulting 2D image into a normal slide projector. The projector projects the image into a cylindrical container filled with acrylate (a synthetic resin). As the projector rotates through the omni-directional image, the container also rotates at a corresponding angle. Taylor, an electrical engineer at the University of California, Berkeley, said: "When a cylinder rotates, any position that receives light can be controlled separately." "If the total amount of light exceeds a certain value, the liquid becomes solid."

△ A chemical in the resin absorbs photons, and when the absorbed photons reach a certain threshold, the acrylate polymerizes to form a solid plastic. The remaining liquid is then removed, leaving behind a solid 3D object. After a few tens of seconds, a portrait was printed in 3D in the cup. This speed is going against the sky! It's much faster than Carbon's CLIP continuous liquid level printing technology. When the cup is rotated, the object can be printed.

△ "Volume 3D printing technology" core ideas

△ core mathematical formula

The core of this system is the CAL algorithm, and it is not easy to actually print. The reconstruction of the 3D model is first performed, including the 2D Fourier transform. It is then necessary to optimize the dose of the photosensitive liquid and the like. In the printing process, problems such as oxygen suppression, light field interference, and conversion matching between 3D space and 2D projection are also involved.

△ Other objects produced by "volume 3D printing technology"

Author of the paper "Volumetric additive manufacturing via tomographic reconstruction" (Science 31 Jan 2019; eaau 7114; DOI: 10.1126/science.aau7114), from UC Berkeley and Lawrence Livermore National Laboratory.

After the publication of the above paper, a Beijing-based Antarctic bear fan Wu Xiang was very excited and immediately complained to the Antarctic bear: the author of this paper copied his patent application in 2015, and he has applied for patents in China, the United States and Europe.