Here’s a photograph of some railway workers in the 1800s posing for one of those new modern things called photographs. It was a moment or, more accurately, a whole series of moments because those early exposure times were long. This is why we always see pictures of people posing and never doing any actual work. All the same, work must have been done or else railways wouldn’t have gotten built.
You can think of the built part of the railway as the material supply path and the workers as a primitive kind of 3D print head that positions those materials where they need to be before the materials supply and print head both move to the next position. A single bricklayer is both material supply path and print head but larger projects having higher walls needed hod carriers to keep the bricklayers continuously supplied with bricks and mortar. All the time. It’s not difficult to see the attraction 3D printing has for the construction industry.
This is Ernst Neufert’s 1943 House Building Machine. Times being the times, Neufert would have thought of this as a moving factory for the assembly of building components that had been made at other factories. It’s really just scaffolding on wheels but Neufert wanted us to think of it as a gigantic 3D printer with the enclosing building as the print head. And we can inasmuch as construction materials are continuously fed in it at one end and a somewhat linear building continuously output at the other.
Ernst Neufert is the very same Ernst Neufert whose book, Architect’s Data, first published in 1936, provided standardised dimensions for building components, minimal space requirements for room types, and standard configurations for building typologies. Neufert was ahead of the curve for seeing the possibilities of prefabrication, and saw standardization as a prerequisite for factory production. His book remains an essential reference for students in some countries even if Metric Handbook is used more widely in practice.
Neufert’s dream of a house-building machine never came to pass in the horizontal dimension but something similar did happen for the vertical with tower cores and, increasingly, columns being slip-formed in concrete. Reinforcement may be craned in and concrete may be pumped into position but a small yet invisible contingent of construction workers is there to place it all accurately and distribute it appropriately. This is getting closer to our image of what a 3D printer should be.
Parallel to this potted history of construction was the development of 3D printers as a development of 2D inkjet printers developed as replacements for thermal printers and the daisy wheel and IBM Selectric (“golfball”) text printers before them.
Each depended upon print materials and a print medium being supplied and forced together to transfer this thing called information. Laser printing does the same thing faster because the letters that are the units of information are created in the same way by pixel dots that are the units of image creation. This meant that laser printers could print images and not just text like a typewriter. This handicap was understood because, before inkjet and laser printing there used to be this think that’s now known as typewriter art. [“Grandpa, what’s a typewriter?”]
Photographic printing involves the batch exposure of materials for batch chemical processing but the action of the chemicals is slow yet theoretically the better way to do things. Semiconductor and integrated circuit manufacturing has no time for the sequential operation of even laser print heads. Instead, circuit boards are photo-printed by a process called photolithography using photomasks and photoresists which are the equivalents of photographic negatives and film.
Despite printer ink being second only to scorpion venom as the most expensive liquid on Earth, the inkjet printer itself is neither complicated nor expensive. All the do is force a liquid through a nozzle in a programmed manner to create ink drops that are then left to dry. This principle can be transferred to other applications.
Three-dimensional printing is more complex because it involves doing the same thing with a substance having more substance than ink but the first 3D printers had much the same mechanics as inkjet printers. The only difference was that, instead of a substrate material such as paper, the previous layer became the base for the next layer and a three-dimensional object was built-up layer by layer. This is why 3D printing is sometimes called additive manufacture. Whereas an inkjet printer print head moves in only one dimension and the paper moves in another, the print head of a 3D printer move in three dimensions in order to form a stationary object. [Having the object move around a stationary print head (as with a sewing machine) is also possible but the technology never went that way.]
Miniaturization into a desktop 3D printers invites us to accept them as part of the business or household just as we did for beige 2D printers.
Early 3D printers had low resolutions acceptable only for the new task of “rapid prototyping” but, by 2010, improved resolution and more sophisticated interfaces allowed the manufacture of end products.
3D Printing in Medicine
Organoids are artificial living tissue created by layering living cells (a.k.a. “bionic”) instead of plastic or metal. Organoids mimic the structure of actual organs, can be used for research purposes and one day may be suitable for use in transplants.
3D printing can be used to quickly and inexpensively manufacture customized prosthetic limbs and body parts. The lower price makes them especially suitable for children who quickly outgrow prosthetics.
A jawbone has been successfully 3D printed from titanium powder with a bioceramic coating, fitted with a dental bridge with new teeth and successfully implanted in an elderly patient. In general, the field of dentistry uses many small-scale prosthetics such as braces and dentures and can benefit from the time and cost advantages of 3D printing.
3D printed synthetic cartilage is now available for knee replacement, as well as 3D printing for knee realignment.
3D printing is particularly suited to the field of medicine because
- the final printed objects are still relatively small,
- the process of 3D printing is inherently suited to the production of the customized, one-off objects used for medical purposes, and
- body organs and parts are generally unseen so aesthetics is rarely an issue.
I could add a fourth. - nobody is suggesting everyone have various body parts replaced with 3D printed ones just because the technology exists.
In general, as long as the desired mechanical and functional properties of an object are understood then the choice of material is unimportant as long as those properties are replicated. This is especially true for medical fields but it also true for any other.
3D PRINTING REDUCES THE NUMBER OF MANUFACTURING PROCESSES TO ONE, ALONG WITH THE NUMBER OF REQUIRED MATERIALS. THIS IS ATTRACTIVE TO ANY INDUSTRY.
The construction industry has been eyeing-up 3D printing for quite some time now because:
- It promises spatial enclosures that can be continuously constructed using a single material and a single process – with obvious savings for construction time and sequencing but also for materials sourcing. The thinking goes that the fewer processes the better and the fewer materials the better and, following on from that, the fewer construction joins the cheaper and better.
- Skilled labour can be eliminated along with the unskilled.
- Huge economies of time and thus money can be achieved. Whether these savings would ever be passed on to consumers is another matter. History suggests not.
What we have is a product that the construction industry wants badly despite society moving in a direction where we’re going to need more things for people to do, not fewer.
It should be clear by now that factory production of anything is more likely to result in unemployment than more leisure time for all. There were once people called craftsmen who used to take pride in making things by hand. 3D printing is the endgame of a century-long process of dehuman-ing manufacture.
3D printers are becoming smaller and a coffee vending machine of the future may yet print the cup while the coffee is brewing. 3D printers are also becoming larger and some of the first house printers were no more than nozzles attached to gantries.
Floors aren’t a problem as they’re flat and supported anyway. Walls also aren’t a problem if the 3D goo hardens quickly enough. However, corners need to be rounded for additional stiffness once window and door openings are made and lintels could be integrated with the door and window frames. Horizontal ceilings are a problem as there’s suddenly no support. However, corbelled and vaulted roofs are possible if the goo sets fast enough. [Perhaps it’s time to study medieval architecture and construction again.] This next image of those 3D printed houses was making the rounds a few years back. The walls corbel outwards, and then inwards to become the roof. It makes no difference whether or not we like or want our houses to have rounded corners inside or out. The construction industry builds what is easy for the construction industry to build and then sells it to us. And then sells it to us.
It seems to be what we’re being led to believe the future will look like. The only difference is that these next variants proposed for Mars won’t have the pretense of individuality. I like how tension bars span the vision panels to prevent the house exploding. Not having one’s house explode is always a good thing but, on Mars, full-height windows are about as necessary as Juliet balconies. It follows in the long architectural tradition of drawing attention to a problem chosen to showcase how clever the solution is.
Materials that can be used for 3D printing include ABS plastic, PLA, polyamide (nylon), glass filled polyamide, stereolithography materials such as epoxy resins, silver, titanium, steel, wax, photopolymers and polycarbonate. NASA invited the big architectural players to submit designs for 3D printed buildings on Mars and, somewhat cheekily, also asked them to not only develop the technologies to make it work, but preferably also using local materials such as Mars regolith since that looks like being the only thing, apart from cold, that Mars has a lot of. The lack of humus in this regolith might be a good thing for 3D printing but that’s not to say inorganic components such as silicon, aluminium, iron potassium and iron won’t cause problems, especially when they come into contact with water. [Won’t everything with iron in it rust? Remember that chemistry class when the teacher threw some potassium into a bowl of water?]
The proposal by Foster & Partners involves three construction stages, each with dedicated robots. The first was digging a hole, the second was putting some sort of inflatable in it and the third stage I didn’t really understand involved using microwave robots to “fuse” the Martian “soil” to the habitat.
Imagining me on Mars, I’d be more concerned about the very process of 3D printing where the gap between every two built-up layers is a potential line of fracture. Think of what happens when your inkjet printer heads need cleaning and those white lines appear due to clogged nozzles? Surely it’d be easier to dig a hole and use the stuff dug out of the hole to make bricks like we used to on Earth?
I recently read that “Scientists have developed a method to 3D-print greener buildings using local soil that they say has the potential to revolutionise the construction industry.” The breathless article leader said “Eco-friendly technology could potentially replace concrete and revolutionise sector”.
This row of houses we recently saw was late to the party in 1830 but, like many similar London terraces built over the hundred years previous, was made out of bricks fired from clay obtained by digging the basements.
These next four proposals all employ a lo-tech shell to shield a technical membrane provided with a breathable mixture of gases at a familiar pressure. Seriously, I don’t think the fourth one’s a starter as it’s made of ice when we don’t know if Mars even has water. Just because it’s cold doesn’t mean there’s ice.
Here’s an idea. We won’t have that much else to do so, rather than unpacking and assembling 3D printers, we could occupy ourselves with productive work using simple, failsafe and low-energy devices.
I’ve prepared a simple design that uses Mars-bricks to enclose maximum volume with the minimum of materials, and in a structurally efficient manner. It looks like this.
The recessed entrance should keep out much of the cold and dust and the walls will protect us from solar radiation. We might still have a problem with the 1% air pressure making our blood fizz like a can of Pepsi and killing us in seconds or, if miraculously not, the 95% carbon-dioxide atmosphere suffocating us in minutes. Until I can scrounge an air-lock from a skip somewhere, I think I’ll follow the principle of every other proposal and keep my technical membrane on when inside my protective shell. On second thoughts, I think I’ll just hang out in the spaceship for a while and do a bit of tidying up. You guys go on ahead. It might take a while.
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