Science and Technology Daily, Beijing, April 20 (Reporter Zhang Mengran) Although 3D printing technology has made great progress in the past decade, the technology still faces a fundamental limitation: objects must be built layer by layer.
US researchers have developed a method for printing 3D objects within a fixed volume of resin.
The printed object is completely supported by thick resin, like an action figure floating in the center of a piece of jelly, which can be added from any angle.
The new 3D printing system, published today in the journal Nature, makes it easier to print increasingly complex designs while saving time and materials.
"This ability to print in volume allows you to print very difficult objects," said Dan Congreve, an assistant professor of electrical engineering at Stanford University. "This is a very exciting opportunity for 3D printing."
On the surface, the technique seems relatively simple: The researchers focus a laser through a lens and shine it into a gel-like resin that hardens when exposed to blue light.
But the researchers didn't simply use a blue laser because the resin would cure along the entire length of the beam.
Instead, they used red light and some cleverly engineered nanomaterials dispersed in the resin to produce blue light only at the precise focus of the laser.
By moving the laser around the resin container, they were able to create detailed, unsupported prints.
The researchers specifically used a method called triplet fusion upconversion to convert one wavelength of light to another.
By bringing the right molecules close to each other, the researchers create a series of energy transfers, such as converting low-energy red photons into high-energy blue photons.
Through a series of steps, the researchers formed the necessary upconversion molecules into different nanoscale droplets and encapsulated them in a protective silica shell.
They then distributed the resulting nanocapsules throughout the resin, with each nanocapsule 1,000 times smaller than the width of a human hair.
The researchers are currently exploring the possibility of simultaneous multi-dot printing, which would greatly speed up the process, as well as printing at higher resolutions and smaller scales.
The researchers are also exploring other applications using upconversion nanocapsules, which will help increase the efficiency of solar panels by converting unavailable low-energy light into wavelengths that can be harvested by solar cells.
The new technology could also be used to help researchers more precisely study biological models that can be triggered by light, and even provide topical treatments in the future.
[Editor-in-chief's circle]
The term 3D printing that we are familiar with is actually a common name for additive manufacturing technology.
The so-called additive is to superimpose the material layer by layer to form the required solid model.
The advantages of this manufacturing method are obvious, such as low cost, fast, automatic, precise and so on.
However, its defects cannot be ignored, that is, the "step effect" of layered manufacturing - although each layer is very thin, at a certain microscopic scale, a "step" with a certain thickness will still be formed. If the surface is required to be very smooth, it will also cause deviations in accuracy.
Now the emergence of this new achievement perfectly overcomes some of the limitations of 3D printing, making this amazing technology truly limitless.