Imagine a world where we will print our own goods. Download your favorite fashions from the internet and click a button to print the garment from a machine. Biomedical engineers would be able to design and fabricate custom prosthetic limbs specifically for the patient instead of mass produced alternatives. More amazingly, doctors would be able to print out biological organs like hearts and kidnies from layer by layer from so called “bio ink” to match to a specific genetic requirements. Although, may seem far stretched from the reality, many experts believe the day we will do this at our home is not far away, thanks to a technique called 3D printing.
3D printing or “additive manufacturing” in fancy terms, a technique that allows a user to print a 3D object from a printer. Much like you print your documents on a page, 3D printer put out materials, whether it be, plastic, metal or concrete to fabricate a 3D object. Unlike a normal printer that just print one layer of ink on to a paper, 3D printer, print multiple layers of materials on top of each other, shaping the object one layer at a time.
3D printing next step
3D printing is not new and has been around since 1980’s. However, one crucial limitation of additive manufacturing is its scale. Until recently, the method could only accurately manufacture objects having the macroscopic resolution, typically measured in tenth of millimeters. This presents a major limitation in fabrication of complex objects. For an example wrist watch has number of very small components with fine details. For future 3D printers to print items like wrist watches, electronics or organs for that matter, the resolution should be in nano or micrometer scale. Having the ability to fabricate objects at this fine scale would not only be a great leap in 3D printing but also will significantly influence the advancement of other technologies as a whole.
3D printing at the nanoscale
A huge step in the right direction was pioneered by a group of scientists from Vienna University of Technology who have made a breakthrough in high resolution 3D printing using a method called “two-photon lithography”. With this technique, nanoscale printing has become a routine job. In two photon lithography, objects are made by hardening of resin molecules which are activated by a laser light. However, these resins are specially designed by chemists to only undergo chemical reaction only if they absorb two photons (light particles) of the laser beam at once. This happens only at the very center of the laser beam where the intensity reaches its maximum. Due to this reason, a very fine spot having nanoscale dimensions get hardened even if the laser spot is in the size of millimeters. In contrast to other techniques, resin can be hardened anywhere in the liquid resin, through focusing of the laser beam to the precise location. Hence, this method can be used to make objects with finest details at a high rate of manufacturing.
This 3D micro-printing technology was taken in to its next level by a company called “nanoscribe” who uses the same technique for 3D microprinting and micro rapid prototyping. The nanoscribe team has shown that their techniques can fabricate elaborate nano and microstructures that can readily be used in applications like, photonic crystals, optical interconnects, tissue engineering scaffolds and unique three dimensional filters. They have also launched, worlds first 3D microprinting instrument that can fabricate intricate micro and nanoscale 3D structures including beautiful human sculptures on a single strand of hair. Nano artworks of Jonty Hurwitz received the Guinness world record for smallest human sculpture in the world fabricated using this method.
A small video of the 3D printing process.