3D printers already create human tissue, a house and smart ‘skin devices’, so what will future bring?
Breakthroughs see technology used to make body parts such as corneas, a home in 52 hours, lightweight cars and electronic devices worn on the skin
Much of the hype around three-dimensional (3D) printing is materialising before our eyes.
The World Economic Forum predicted in 2015 that the process of making a physical object from a three-dimensional digital model, typically by laying down many thin layers of a material in succession would “change the world”.
The potential uses of 3D printing are limitless.
Body parts, such as corneas …
The proof-of-concept research, led by Dr Steve Swioklo and Professor Che Connon, involves using stem cells from a healthy donor’s cornea and mixing them with alginate and collagen to create a solution – a “bio-ink” – that could be printed.
Using a simple, low-cost 3D bio-printer, the bio-ink was successfully forced out in concentric circles to form the shape of a human cornea. It took less than 10 minutes to print.
Over and above traditional manufacturing processes, the technique allowed “for rapid manufacture with bespoke properties, thus each cornea could be made specifically for that patient at the point of care”, Connon said.
“Also as the cornea is composed of layers of different structured tissue containing different cells, the layer-by-layer approach [of 3D printing] suits this very well.”
He said the technique could be used to ensure “unlimited supply of corneas” for the millions worldwide who require surgery to prevent corneal blindness as a result of diseases such as trachoma, an infectious eye disorder, or suffer total blindness due to corneal scarring.
“Many teams across the world have been chasing the ideal bio-ink to make this process feasible,” Connon said.
“Our 3D-printed corneas will now have to undergo further testing and it will be several years before we could be in the position where we are using them for transplants.”
A house printed in 54 hours …
Their four-bedroom property took 54 hours to print, at a cost of about £176,000 (US$230,000) – 20 per cent cheaper than an identical construction using more traditional solutions.
Next year in the city of Eindhoven, in the Netherlands, residents of the world’s first commercial housing project, based on 3D-concrete printing, should start to receive their keys.
The five futuristic-looking homes in Project Milestone will be sustainable and energy-efficient, but also made with comfort in mind.
More than an experiment, the developers said “these houses are intended to be occupied for at least several decades”.
Because of its ability to construct almost any shape, quality and colour, the 3D printing of concrete opens up endless possibilities for the building industry.
“Another important advantage is sustainability, as much less concrete is needed and hence much less cement, which reduces the CO2 emissions originating from cement production,” the developers said.
A car, with most visible parts printed …
Polymaker said three crucial achievements made this possible.
First, the number of components in the car has been reduced from more than 2,000 to only 57; the finished LSEV weighs only 450kg (about 0.44 tonnes, much less than similar sized vehicles, which usually weigh between 1 and 1.2 tonnes.
Second, apart from the chassis, seats and glass, all the visible parts of the car are made by Polymaker materials through 3D printing. This switch in production leads to a more than 70 per cent reduction in the investment cost compared with a traditional production system.
Lastly, a new design XEV can be completed in three to 12 months, compared with three to five years for the conventional research and development process of a car model.
XEV said it had already received 7,000 pre-orders, including 5,000 from Poste Italiane, the Italian postal service.
Mass production is expected to start in the second quarter of 2019.
Even smarter objects in the home …
Yet what potential does 3D printing hold for those of us at home?
The use of 3D-printed objects may improve the current state of the Internet of Things (IoT) – the network of physical devices, vehicles, home appliances and other items embedded with electronics, software and sensors, which enables these things to connect, collect and exchange data.
Imagine a bottle of laundry detergent that can sense when you are running low on soap – and automatically connect to the internet to place an order for more.
Researchers at the University of Washington, in Seattle, US, are possibly the first to make this a reality by 3D-printing plastic objects and sensors that can collect useful data and communicate with other Wi-fi-connected devices entirely on their own.
“Our goal was to create something that just comes out of your 3D printer at home and can send useful information to other devices,” Vikram Iyer, an electrical engineering doctoral student at the university and co-lead author of the research paper on their work, said.
“But the big challenge is: how do you communicate wirelessly with Wi-fi using only plastic? That’s something that no one has been able to do before.”
To 3D-print objects that can communicate with commercial Wi-fi receivers, the team employed backscatter techniques that allow devices to exchange information.
Backscatter systems use an antenna to send data by reflecting radio signals emitted by a Wi-fi router or other device.
Borrowing from principles that allow battery-free watches to keep time, the team replaced some functions normally performed by electrical components with parts that can be 3D printed.
Physical motion – such as laundry liquid flowing out of a bottle – triggers the communication process.
“The receiver can then track how much detergent you have left and when it dips below a certain amount, it can automatically send a message to your Amazon app to order more,” Shyam Gollakota, an associate professor at the university’s Paul G. Allen School of Computer Science & Engineering, said.
The team is now making computer-aided design models available to the public, which means 3D-printing enthusiasts are able to create objects out of commercially available plastics that can wirelessly communicate with other smart devices, such as a battery-free slider that controls music volume, or a water sensor that sends an alarm to your phone when it detects a leak.
Wearable electronic devices – printed on skin …
If you cannot decide which smartwatch to buy, fear not: you may not have to fret for too much longer.
Researchers at the University of Minnesota, in the US, have worked out how to print 3D electronics directly onto the skin.
It is done using a portable, lightweight printer costing less than US$400.
Michael McAlpine, the university’s associate professor of mechanical engineering, said one of the key innovations of the technique was its ability to adjust to small movements of the body during printing.
Temporary markers are placed on the skin, which is scanned, and the printer then uses computer vision to adjust to movements in real-time.
“No matter how hard anyone would try to stay still when using the printer on the skin, a person moves slightly and every hand is different,” McAlpine said.
“This printer can track the hand using the markers and adjust in real-time to the movements and contours of the hand, so printing of the electronics keeps its circuit shape.”
Printing electronics on skin “has unlimited potential for important applications in the future”, McAlpine said.
“In everyday lives, you can imagine your family eventually printing their next smartwatch directly on their skin.”
To remove it, the electronics can be peeled off with tweezers, or washed off with water.
“We are probably, [a] minimum [of] 10 years away from this, but eventually the printers may be portable enough that you can carry one around in a backpack and print sophisticated devices anywhere,” McAlpine said.
So what is coming next?
A research team at City University of Hong Kong has made a breakthrough in 4D printing – for ceramics.
Professor Lu Jian, the university’s vice-president of research and technology and chair professor of mechanical engineering, said 4D printing involved conventional 3D printing combined with the additional element of time as the fourth dimension.
It involved the printed objects being able to re-shape or self-assemble themselves over time with external stimuli, such as mechanical force, temperature or a magnetic field, he said.
The team’s development of “ceramic ink” – a mixture of polymers and ceramic nanoparticles – is a groundbreaking advancement in materials research, which could mark a new stage in the structural application of ceramics used in the manufacture of electronic devices, the aerospace industry and space exploration.
“Ceramics cannot be cast or shaped easily because of the material’s extremely high melting temperature,” Lu said.
“Furthermore, the existing 3D-printed ceramic precursors are usually difficult to deform, hindering the production of ceramics with complex shapes.”
The 3D-printed ceramic precursors printed with this ink are soft and can be stretched three times beyond their initial length, enabling complex shapes, such as origami folding.
“With the versatile shape-morphing capability of the printed ceramic precursors, its application can be huge,” Lu said.
With the arrival of 5G networks, ceramic products would start to play a more important role in the manufacturing of electronic products, Lu said.
“The artistic nature of ceramics and their capability to form complex shapes also provide the potential for consumers to tailor-make uniquely designed ceramic back plates for mobile phones.”