Lesson 1:
What is 3D printing?
3D printing is a manufacturing technique that allows the creation of a three-dimensional object from a digital model designed on a computer. In the following video you can see a 3D printer in action, printing a small figure:
However, as we will see throughout the unit, there are many materials that can be used in this type of printing and there is a wide variety of different 3D printing techniques.
When did it come up?
Despite what you may believe, it is a technology that has been in development for quite some time.
– Already in the 70s, shortly after the invention of ink printers, the possibility of printing in 3 dimensions and with different materials began to be investigated.
– Along the next decade, some 3D printing systems began to be patented, the first of which was known as stereolithography (which will be explained later). This technique was discovered by engineer Charles W. Hull in 1986 and marked the beginning of the development of 3D printing.
– At the end of the 80s and during the 90s, new 3D printing techniques continued to develop: fused deposition modeling, selective laser sintering, selective laser fusion, electron beam manufacturing … some of them will be explained later. Throughout these years, new applications of 3D printing began to emerge, mainly in the field of medicine, with the manufacture of prostheses (such as the hip prosthesis in the image) and dental implants, even the first ones being manufactured. organs for transplantation with human cells.
How did 3D printing become popular?
– In the first decade of the 2000s most of the printing techniques had already been invented. However, until that time the 3D printers that had been developed had a very high price, so they could only be purchased by research centers or companies with a large budget. During these years, printers began to be manufactured at much lower costs, so they began to be used in a greater number of projects.
– This reduction was due, among other factors, to the emergence of open source projects (non-profit projects) that allow a large number of companies and individuals to create and improve their own 3D printers. In this type of project, both, the designs of the parts and the software are available to everyone who wants to use it or improve it.
Two quite innovative projects that facilitated the spread of 3D printing are:
- The Rep Rap project: which emerged in 2005 with the aim of designing a 3D printer whose parts could be printed by another 3D printer (self-replicating machine). In this way, the cost of manufacturing this type of machine was drastically reduced. This project allowed anyone with minimal knowledge to be able to manufacture (in the absence of some components such as motors) and assemble their own printer, as well as repair it with minimal cost. In the following link you can obtain more information about the project: https://reprap.org/wiki/RepRap
- The Fab@Home project: it is a 2006 project that aimed to develop a 3D printer accessible to everyone and capable of printing a wide variety of objects. The big difference compared to the previous project is that in this case it was about printers that could print several different materials, having come to create machines that could print up to 8 materials: different types of plastics, metals, cells, food … To achieve this, the printers in this project have a certain number of syringes (as can be seen in the image) that deposit the different materials in the appropriate position.
– Finally, from 2010 we have witnessed a true revolution in 3D printing. This has reached a large number of people who have seen in it the possibility of manufacturing, cheaply and quickly, a multitude of items that they would otherwise be forced to buy. The low prices at which one of these machines can be purchased today (less than 200 euros) has enabled its expansion not only at a professional level but also at a private level.
In addition to this price reduction, user communities have been created (one of the best known is https://www.thingiverse.com/) in which there are countless totally free designs that can be downloaded and printed In a simple way. Among those designs you can find:
Spare parts 
Protection masks 
Molecule models
3D printing applications.
As will be explained on the next page, the great advantage of 3D printing as a manufacturing method lies in the ability to design completely custom parts for a specific purpose. It is this characteristic that has made this technology applicable in sectors such as:
- The pharmaceutical industry: one of the latest applications of this technology is in the manufacture of customized medicines for patients. 3D printing allows pills to be printed with the exact amounts of each active ingredient and with the most appropriate shape to facilitate their dispersion.
- Architecture: the manufacture of models by 3D printing makes the task of projecting structures and buildings much easier. In addition, as will be seen in a later video, there are already large printers capable of printing homes, and other structures such as bridges, with construction materials.
- Gastronomy: another application of this technology is in the preparation of food, mainly for aesthetic purposes, hence it is applied especially in confectionery.
- Fashion industry: it has been one of the last sectors to join the 3D printing revolution. Initially, this technology was used only for the creation of prototypes, facilitating the creative process of designers. However, nowadays they are already used for the manufacture of the garments themselves, which brings advantages such as the absence of seams and the adaptation to the user’s body. The manufacture of custom footwear is also currently being investigated by some companies that already manufacture shoes with printed parts like the one in the image, whose heel has a hexagon structure that would be very difficult to reproduce by other methods.
- Research and education: printing certain models (of atoms and molecules for example) or three-dimensional figures can help to better understand the world around us.
- The automotive industry: it is already common to print certain parts for cars and motorcycles. This is especially useful when manufacturing highly complex parts, since 3D printing allows the amount of material to be reduced, considerably reducing the weight of the vehicle. The Strati (image) is an electric car model whose parts are printed in a mixture of carbon fiber plastic and which takes less than 48 hours to manufacture. Furthermore, unlike conventional cars, which have more than 20,000 parts, this model does not exceed a hundred between printed parts and non-printed mechanical components (engine, wheels, batteries, wiring …).
- The aerospace industry: in November 2018 a 3D printer was installed on the international space station.
The Refabricator system by the US-based aerospace company Tethers Unlimited Inc. (TUI) has been installed on the International Space Station (ISS). The integrated 3D printer and plastic recycler was launched into space in November last year.
https://3dprintingindustry.com/news/nasa-installs-tether-refabricator-aboard-iss-for-in-space-3d-printing-148728/
Not counting the wide variety of medical applications that have continued to be developed: biocompatible bone implants, skin grafts for the treatment of burns, manufacturing of surgical material tailored to the patient …
In the following videos you can see some of the most striking uses of 3D printing, some of which have already been mentioned above:
As explained in the last video, 3D printing makes the manufacture of certain products much cheaper.
I invite you to think about all the 3D printing projects that have not yet been carried out and that could improve the quality of life of a large number of people, especially those with fewer economic resources. Finally, I leave you a video about one of the non-profit projects that have been developed throughout the world:
However, not all projects related to 3D printing have been as beneficial to society as those in the previous videos. I leave you a piece of news that represents very well the dangers that technological development can bring:
Less than a decade ago, millions of people had no idea what 3D printing was and learned about it for the first time when the headlines of international news read “3D printed guns”. Years after the first 3D printed gun was created, people and governments still discuss this topic, the opinions are divided.
https://www.3dnatives.com/en/3d-printed-gun-020920205/#!
Remember, technology is not bad or dangerous itself, we are the ones who sometimes misuse it. It is in our power to direct all technical advances towards the improvement of our society and if you achieve it we will not find anything more than advantages in its development.
