SLA 3D Printing: Chinese Researchers Create Strong Ceramic Molds with Non-Aqueous Gelcasting

In ‘Rapid Fabrication of High-Performance CaO-Based Integral Ceramic Mold by Stereolithography and Non-Aqueous Gelcasting,’ Chinese researchers from Xi’an Jiaotong University explore 3D printing of better ceramic molds for investment casting. These are extremely important tools in manufacturing for a variety of applications, and mainly for casting structures that are complex and require internal cavities. Most are produced out of silica or alumina with good results, but not when used with active alloys that result in an inferior finish. Here, the authors search for affordable, accessible materials to fabricate ceramic molds that still possess the thermal stability and collapsibility required.

Calcium oxide, or CaO, is the center of focus in this study for a material that would be suitable for the ceramic core of a mold. It offers:

  • Reaction-resistance to molten active alloys
  • Ease of dissolution
  • Similar thermal expansion coefficient to those of superalloys

Morphology and particle size distribution of the CaO powder.

Susceptibility to water is a major issue with CaO, however, limiting its uses, along with inferior mechanical properties and low density. The researchers experimented with SLA 3D printing and gelcasting, which offers a unique method for creating ceramics via in-situ solidification. The more typical aqueous gelcasting was not a possibility due to hydration issues, but the authors were aware of previous experiments with non-aqueous procedures.

“Tert-butyl alcohol (TBA) has been selected as the solvent due to its low surface tension and high saturation vapor pressure, and the green body can be dried easily and with little shrinkage,” reported the authors.

CaO powder was combined with a pre-mixed solution and then the slurry was poured into a resin mold 3D printed on a SPS600B Rapid Prototyping Machine.

“The green body was subsequently placed into a vacuum freeze-dryer (Beijing Songyuan Huaxing Technology Development Co., Ltd., Beijing, China) with a freezing temperature of −40 °C, shelf temperature of 0 °C, and pressure of 10 Pa for 48 h. Finally, an integral CaO-based ceramic mold was obtained after sintering at 1400 °C for 3 h.,” explained the researchers in their study.

 

Schematic diagram of the integral ceramic mould manufacturing process.

The researchers were able to create a stronger slurry with some adjustment, along with gelation. Cracks were a major concern too, so temperature and heating rate had to be managed accordingly:

“There were no cracks in the CaO-based ceramic crucibles when the heating rate was 0.5 °C/min or 1 °C/min, whereas there were obvious cracks in the crucibles when the heating rate was greater than 1.5 °C/min. Although the ceramic mold did not crack with a heating rate of 0.5 °C /min, the heating rate is too low to facilitate efficient and economical production rates. To balance the quality, efficiency and energy consumption of manufacturing, 1.0 °C/min was considered the most suitable heating rate for pre-sintering the CaO-based ceramic molds,” reported the researchers.

Pre-sintering and sintering were also rigorously managed to control shrinkage, resulting in a low rate of 0.6% and a relatively high high-temperature (1200 °C) bending strength of 8.22 MPa.

“Compared to the injection molding process, the process described in this paper is more efficient for the fabrication of molds with complex structures and cores. The fabrication process of the CaO-based ceramic mold developed in this study is ideal for the rapid manufacturing of active metal parts with complex cavities,” said the researchers. “The process is more suitable for the rapid manufacturing of single-piece or small-batch production than the mass production due to the low efficiency of SLA. The control mechanism and method of near-zero shrinkage and the casting performance of CaO-based mold still need to be considered in further study.”

In a world still held undeniably connected between conventional methods of manufacturing and the mind-blowing progressive, the two commonly intersect—and 3D printing is often used today for making molds so that users can go on to make multiple objects quickly, and often with materials not supported by 3D printing, yet. And although the innovations brought forth by 3D printing are often staggering in their novelty as well as functionality, users around the world have been on a steep learning curve, driven to make one powerful improvement over another.

Find out more about other 3D printed molds such as those used to make elaborate metal architectural structures, glass molds, and PDMS molds for microfluidic designs. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

Images of CaO-based parts with different pre-sintering heating rates: (a) 0.5 °C/min, (b) 1.0 °C/min, (c) 1.5 °C/min, and (d) 2.0 °C/min.

[Source / Images: ‘Rapid Fabrication of High-Performance CaO-Based Integral Ceramic Mold by Stereolithography and Non-Aqueous Gelcasting’]

3D Printing News Briefs: April 6, 2019

We’re starting off today’s 3D Printing News Briefs with a product launch announcement – 3YOURMIND launched the full version of its Agile MES software software this week at AMUG 2019. Moving on, Sintratec will present its latest SLS 3D printer at RAPID + TCT next month in Detroit, Tiamet3D has joined Ultimaker’s material alliance program, and Sciaky entered into an agreement with KTM Consultants. Xometry just announced some important certifications, and nScrypt is 3D printing titanium parts. Moving on to the world of art and theatre, the Zurich Opera House is 3D printing props, and artist Andrea Salvatori worked with WASP to create a 3D printed art collection.

3YOURMIND Launched Agile Manufacturing Execution System (MES) Software

After spending five years providing order management systems to scale for some of the industry’s AM leaders, 3YOURMIND has finally moved its software solutions to a production environment with the launch of its Agile Manufacturing Execution System (MES) earlier this week at AMUG 2019. The software uses smart part prioritization, rapid scheduling, order tracking, and custom AM workflow creation to improve machine utilization and make production more efficient, and an Early Access Program (EAP) allowed the company to receive direct feedback on its Agile MES software from representatives at companies like EOS and Voestalpine. The next step will be working to finalize machine connectivity.

“For Agile Manufacturing, the Agile MES will need to both GET and PUSH data from all major AM machines and post-processing systems. We are already integrating the data from several vendors into our software and expect to support all major machines,” explained 3YOURMIND’s CEO Stephan Kühr. “Receiving and processing machine data allows us to provide the documentation that is needed for quality assurance and to increase the repeatability of additive manufacturing. Pushing data directly to machines will be the key to automating production.”

Sintratec Showcasing New SLS 3D Printer at RAPID + TCT

A few months ago, Swiss SLS 3D printer manufacturer Sintratec introduced its scalable, modular Sintratec S2. Now, the company will be presenting the printer in the US for the first time next month at RAPID + TCT in Detroit, which will also be Sintratec’s first time attending the massive event. What makes the Sintratec S2 stand out is its closed-loop workflow, as the complete system covers every process with its three modules: the Laser Sintering Station (LSS), the Material Core Unit (MCU), and the Material Handling Station (MHS). The 3D printer offers quick material changes, a 4K camera for print monitoring, improved ergonomics, and effective heat distribution through its cylindrical printing area and ring lamps.

“The Sintratec S2 will boost the design of applications and gives the user the opportunity to set foot in small series production as well. And that for an unusually attractive price-performance ratio,” said Sintratec CEO Dominik Solenicki.

“With the Sintratec S2 solution we will be opening new opportunities for companies of any size.”

The price for the Sintratec S2 starts at $39,900, and you can see it for yourself at Sintratec’s booth 1753 at RAPID + TCT from May 20-23.

Tiamet 3D Joins Ultimaker’s Material Alliance Program

Last year, Dutch 3D printing specialist Tiamet 3D, founded in late 2014, worked with Finland-based Carbodeon to develop the first nanodiamond-enhanced 3D printing filaments, which went on the market in September. Now the company has joined Ultimaker as a partner in its Material Alliance Program. Together, the two will offer end-users simple one click downloads of Tiamet’s ULTRA Diamond material profile, which is now available on Ultimaker’s Cura software. This collaboration is formally backed by Tiamet’s manufacturing partner Mitsubishi Chemical Performance Polymers (MCPP Netherlands).

Reid Larson, the Director and Co-Founder of Tiamet 3D, told us about some of the highlighted specs of its ULTRA Diamond material, including no additional nozzle wear, 6300 mpa stiffness, low moisture absorption and friction, improved thermal conductivity, and twice “the temperature resistance of normal PLA, Annealed goes to 125C HDT.” You can purchase one kg of ULTRA Diamond filament for €59.

Sciaky Increasing Sales Efforts Through New Agreement

In an effort to increase the sales efforts of its Electron Beam Additive Manufacturing (EBAM) solutions in Australia, the Middle East, and New Zealand, Sciaky, Inc. has entered into an agreement with KTM Consultants, founded by metallurgist Trent Mackenzie in 2015. In terms of sheer work envelope, Sciaky’s massive EBAM systems are the industry’s most widely scalable metal 3D printing solution, able to produce parts ranging from 8 inches to 19 feet at gross deposition rates of up to 25 lbs of metal an hour. Additionally, its Interlayer Real-time Imaging and Sensing System (IRISS) is the metal 3D printing market’s only real-time adaptive control system capable of sensing and digitally self-adjusting its deposition.

“I was immediately drawn to Sciaky’s EBAM technology because of its unique and robust capabilities. Industrial manufacturers of large metal parts need to explore the significant advantages that technologies like EBAM offer. It is truly a game-changer,” said Mackenzie.

Xometry Announces New Industry Certifications

Digital manufacturing marketplace Xometry announced that it has just received ISO 9001:2015 and AS9100D certifications – some of the most rigorous, widely-recognized quality management designations in the industry. ISO 9001 helps organizations meet the needs and expectations of their customers in terms of quality management, while AS9100 meets customer demands in the exacting aerospace and defense industries. The company went through a major audit as part of the process, and its achievement definitely reflects how committed Xometry is to providing quality.

“We are thrilled to receive this designation. Our team members have a passion for providing great customer service while following the disciplines that give our customers peace of mind regarding on-time delivery, quality, and continuous improvement. It is yet another step towards achieving industry “best in class” status and being able to meet the expanded needs of our customers,” stated Xometry COO Peter Goguen.

nScrypt Develops Proprietary Method for 3D Printing Titanium

nScrypt 3D printed titanium gear, dogbone, and block

Florida manufacturer nScrypt, which develops high-precision Micro-Dispensing and Direct Digital Manufacturing equipment and solutions, is now focusing on repeatable 3D printing of metals for the medical, defense, and aerospace industries. The company has created a proprietary method for 3D printing titanium parts, which tests have shown display densities comparable to wrought parts. This method could easily work with other metals as well, such as copper, Inconel, and stainless steel, and nScrypt’s Factory in a Tool (FiT) systems can finish or polish areas with high tolerance features using its integrated precision nMill milling head. nScrypt’s Brandon Dickerson told us that the company expects to release more details on this later in 2019.

“The parts were printed with our SmartPump™ Micro-Dispensing tool head, which runs on any of our systems,” Dickerson told 3DPrint.com. “The parts shown in the photos were printed on our DDM (Direct Digital Manufacturing) system, also known as our Factory in a Tool (FiT) system, which can run 5 tool heads at the same time, including our Micro-Dispensing, Material Extrusion, micro-milling, and pick-and-place tool heads.  The parts were sintered after the build and the current densities are in the high 90% range.  We expect our system to appeal to customers who want to do Direct Digital Manufacturing and need strong metal parts, but cannot build them with a powder bed system (for example, if the geometry would trap powder inside) or prefer not to use a powder bed system (for example, if they want a cleaner system).”

Zurich Opera House 3D Printing Props with German RepRap

Finished tutu for “The Nutcracker”, which was produced with the help of the x400 3D printer

Switzerland’s largest cultural institution, the Zurich Opera House, puts on over 300 performances a year, but the behind-the-scenes magic happens in the studios and workshops, where the props and costumes are made. The opera house uses the x400 3D printer from German RepRap, with assistance from Swiss reseller KVT- Fastening, to support its creative work by fabricating props and molds. This affords the institution more creativity and flexibility, as they can design objects to their exacting needs in 3D modeling programs, which also helps save on time and money. The opera house currently uses PLA, which is easy to handle, offers a variety of colors, and is flame retardant – very important in a theatrical setting.

“Often, the wishes and ideas of costume and stage designers are very diverse and sometimes extraordinary. It often happens that props are not available in the way designers have it in their minds. This is where the 3D printer is perfect for,” said Andreas Gatzka, director of theater sculpture at the Zurich Opera House.

“There are a lot of great benefits. Special wishes of stage and costume designers can be realized quickly as well as a short-term change of the objects, for example larger, smaller, longer, shorter, or whatever is needed.”

3D Printed Art Collection

Artist Andrea Salvatori 3D printed the eye-catching pieces for his new collection, titled Ikebana Rock’n’Roll, using the Delta WASP 40100 Clay 3D printer – designed by WASP to be used by ceramic and clay artists. The collection just opened on stage at THE POOL NYC in Milan last week, and will be available to view until May 31st. With these 3D printed vases, Salvatori wanted to use “a miscellany of ceramic insertions” to mess with the high quality shapes 3D printing can achieve by adding asymmetry.

“The process of depositing the material and setting the spheres is a central theme in the Ikebana Rock’n’Roll collection, to the point of convincing Salvatori to name the works “Composition 40100”, as if they originated from a musical dialogue of the most varied tones. The artist upsets the algorithm reiterated slavishly by the machine with imperfect musical accents, the result from time to time of spontaneous actions and reasoned processes,” WASP wrote in a blog post.

“The ikebanes, proposed by Andrea Salvatori in the exhibition, transcend the experimental limits of an abstract investigation, representing a concrete territory in which 3D printing and ceramic art co-exist synergistically. The Master challenges the confrontation with the public, becoming also in this sector, precursor of a new genre in which WASP feels itself fully represented.”

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Nano Dimension and Mayku Announce New Strategic and Distribution 3D Printing Partnerships

Israeli additive electronics provider Nano Dimension announced in April that it would be expanding its coverage in the Asia Pacific (APAC) region, and today has made good on that announcement. The award-winning company has officially entered the Chinese market now, thanks to its strategic partnership with top 3D printer distributor the AURORA Group.

The AURORA Group is the majority shareholder of 3D software and 3D printer provider General Integration Technology (GIT), which recently purchased and installed a DragonFly 2020 Pro PCB 3D printer from Nano Dimension for its Taiwan showroom. In addition to this new partnership, AURORA has also purchased a second DragonFly 2020 Pro.

“China is one of the world’s largest and most important electronics manufacturing and design markets, and establishing the correct foothold in the market is key for Nano Dimension. AURORA has years of operating experience in the manufacturing sector, and with its extensive resources and unique network of 1,500 offices, 300,000 customers, including more than 3,000 customers in electronics industries, we believe it is very well positioned to give us fast market access to realize the full potential of the DragonFly 2020 Pro in China,” said Amit Dror, CEO of Nano Dimension. “We look forward to developing the Chinese market together by leveraging AURORA’s significant presence.”

As a result of the partnership, AURORA will market and sell the DragonFly 2020 Pro to customers in China, which will help grow Nano Dimension’s market coverage in APAC.

“Providing our customers with the very latest in high-quality, innovative 3D printing solutions is key to the success of our company,” said Daniel Chi, GM of 3D Business Unit, AURORA Group. “Forming a strategic relationship with Nano Dimension helps us expand our offering to now include capabilities for 3D printing electronics. The Nano Dimension DragonFly 2020 Pro is a groundbreaking technology that opens unimagined possibilities for electronics designers and manufacturers.”

A January 2018 market research report from the International Data Corporation (IDC) shows that the quickly growing Chinese 3D printing market is leading Asia. 3D printing in the country benefits from both industrial and private consumer investments and government support, so partnering with AURORA for additional APAC coverage is a smart move on Nano Dimension’s part.

“This is an important moment for our recently established Hong Kong office,” said Nano Dimension’s APAC Director Gilad Reshef. “We are proud to partner with AURORA as our leading partner in China. The partnership with AURORA deepens AURORA’s exposure to additive manufacturing by expanding into 3D-printing electronics, paving the way for new markets and applications.”

This news from Nano Dimension and AURORA isn’t the only newly announced 3D printing partnership. London startup Mayku has just released its innovative desktop vacuum former, the FormBox, for sale in the UK and the US, with help from its own new partner – 3D printing specialist GoPrint3D.

The FormBox

“We’re really excited about it as we think a lot of 3D printer owners will want one to complement their existing 3D printer,” GoPrint3D’s David Whitehouse told 3DPrint.com.

A drone case being removed from the mold.

GoPrint3D, which is also a distributor for EnvisionTEC and learnbylayers, was launched six years ago as a part of Express Group Ltd, which has provided 2D printer repair and spare parts to the UK for three decades. The company sells, repairs, and hires 3D printers, in addition to providing professional services.

“We were so impressed when we first saw the FormBox that we immediately backed it on Kickstarter,” explained Jo Young, Managing Director at GoPrint3D. “Now we are a partner as well as a backer. It’s the perfect accessory to 3D printers like the Form 2 so we are delighted to add it to our range.”

In 2016, Mayku crushed its original $50,000 Kickstarter campaign goal for the FormBox by over 1,000%. The desktop vacuum forming machine, which can be powered by a vacuum cleaner, lets makers and designers create items in all sorts of materials, ranging from concrete, ice, and plaster to soap, chocolate, and wax, and others as well.

The machine is user-friendly, and fast as well – able to make molds in just minutes without having to rely on any additional software or digital model manipulation.


“Vacuum forming was previously something found in makerspaces and in schools due to their cost and size,” explained Ben Redford, Mayku’s Co-Founder and CPO. “We are thrilled to have the support of the 3D printing industry and have been blown away with what makers have been designing.”

The FormBox is a complementary new hardware addition for 3D printer owners. Users can easily vacuum form a 3D print using the FormBox, which can then be used as a mold for fast replication in multiple materials that are not able to be directly 3D printed at this time.

GoPrint3D now has the FormBox in stock and available for purchase for a price of £499 excluding VAT.

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Metal 3D Printing and Classic Foundry Techniques: Friends or Foes?

The first question that is often asked when a new technology is introduced is: what of the old way of doing things? Sometimes the answer is that it fades into oblivion — think: fortran and floppy disks — other times it falls out of use in mainstream society but becomes the domain of a small, especially devoted community, like calligraphy or pedal loom weaving. And in other cases, it simply shifts its focus and allows itself to flower as it removes extra ‘noise’ from the workflow. John Phillip Sousa wondered if the invention of the phonograph might cause human beings to lose their vocal chords as they would no longer have to sing any song they wished to hear, and an equally pessimistic (although slightly more realistic) group worried that the Kindle would eradicate books altogether.

What has happened is that humanity has access to more music than ever and book production may see a fall in the print of throwaway paperbacks, but there appears to be no reason to fear that beautiful books will be eliminated from publication. One new technology that is causing both concern and overinflated speculation is the introduction of metal 3D printing. The question is: what impact will this technology have on traditional foundries? Foundry work is not inherently antithetical to 3D printing as many have, in fact, been using 3D printing to create molds for years now and have found the technology to be quite helpful in their production.

Beyond the printing of 3D molds, metal 3D printing is demonstrating a capacity for directly creating metal objects that is improving with each passing project. Voxeljet, which recently produced a new design for aircraft doors using 3D metal printing, doesn’t think that this signals the end of the classic foundry, however. Instead, they see it as something akin to a separate track of printing. What made the doors they produced such a good candidate for 3D printing was the need for a precise internal geometry, something impossible to be produced in a foundry. So rather than stealing work from a foundry, they were doing work that otherwise would not have been performed at all. And there are other reasons not to see metal 3D printing as a threat to foundry work, as voxeljet explained in a statement:

“3D metal printing, such as direct metal laser sintering (DMLS), currently only competes with foundries in a relatively small segment. The build spaces of DMLS systems are ideally suited to smaller components. And 3D-printed components for aerospace require time-consuming certification, which metal casting has had for decades already. Direct 3D metal printing is also relatively expensive. This is not only due to the high cost of metal powder, but also the high cost of 3D printers and the comparatively slow building speeds.”

In addition to these factors, the products of 3D printing in metal require hand finishing which is labor intensive. All of these factors lead up to an average cost for 3D printed metal pieces that hovers around $160 per pound for aluminum, and $215 per pound for stainless steel, whereas pure cast steel has a price point of about $15 per pound. However, with the introduction of less expensive machinery, greater build bed sizes, and a more experienced workforce, the input prices for 3D printed metal are bound to come down. And so the question arises: will there be a change as the costs associated with metal 3D printing fall?

This uncertainty necessarily creates a degree of concern among those whose businesses and livelihoods depend upon a demand for foundry work. Rather than viewing the technology as an enemy to be shut out, perhaps the best solution is for foundries to get ahead of the game and embrace the tech, integrate it into their workflows and determine for themselves what makes sense to leave to a 3D printer and what can still only be produced at the hands of skilled foundry workers. As Ingo Edere, CEO at voxeljet, stated:

“3D sand and plastic printing are a perfect alternative for foundries, both in terms of cost, as well as the printable complexity. Foundries can manufacture equally complex components without having to change the process chain. Foundries do not have to purchase their own 3D printing systems as there are service providers worldwide supplying 3D sand or plastic printing.”

Clearly, a company such as voxeljet believes in the efficacy of this technology and its firm place as part of the landscape of future production. However, just because something can be 3D printed, doesn’t always mean that it should be, and discerning artisans and clients alike are the ones who will ultimately have to determine where that line lies.

What do you think of this news? Let us know your thoughts; join the discussion of this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below. 

 

ETH Zurich Students Cast Elaborate Metal Architectural Structures with 3D Printed Molds

The innovative researchers at ETH Zurich in Switzerland are becoming quite well-known for their advanced design and construction techniques, especially when it comes to their work with molds. 3D printed molds can be used to help fabricate everything from jewelry and chess pieces to medical implants and wind turbines, but a group of masters students from the university’s Architecture and Digital Fabrication course are currently interested in creating 3D printed molds for the architecture field.

Together with ETH Zurich senior researcher Mania Aghaei Meibodi, they have developed a new method for casting complex metal architectural structures using 3D printed molds.

Aghaei Meibodi, who researches how 3D printing can help create bespoke metal building elements, said, “Cast metal parts have a long tradition in architecture due to their extraordinary structural properties and possible 3D form.

“Today the amount of manual labour involved, especially in the mould-making process makes them too expensive.

“With our approach using 3D-printed moulds, we make it possible and affordable again to fabricate bespoke structural metal parts — parts with unseen richness of detail and geometric complexity.

“This approach can unlock an entirely new vocabulary of shapes for metal structures in architecture, previously unavailable with traditional mould-making systems.”

The one-off aluminum structure created by the Digital Building Technologies (DBT) group, called Deep Facade, is the first metal facade to be cast in 3D printed molds. Standing six meters high and four meters wide, the structure features ribbons of metal organically looped in a way that resembles the human brain’s cerebral cortex folds, and is a follow-up to a project by last year’s students called the Digital Metal Pavilion.

Aghaei Meibodi told Dezeen that the aluminum Digital Metal Pavilion, a space-frame structure made up of 240 non-repetitive joints, was the very first architectural structure to use 3D printed molds.

It only took a week to make these joints, which Aghaei Meibodi, who also chairs the DBT group, explained is 80 times faster than the more conventional processes used to fabricate complex metal parts. Using 3D printing for this type of application is obviously a far more cost-effective way to produce complex structures and forms for custom architectural projects.



It is possible to 3D print metal directly, but it’s not always the best option – it can be expensive, and can only be used with a limited range of metals with limited material properties. That’s why the DBT group uses 3D printed sand molds in casting molten metal.

Aghaei Meibodi explained, “In this synergy we benefit from the geometric freedom offered by 3D printing and the structural stability of cast metal.”

The Deep Facade structure is made of 26 articulated panels. A differential growth algorithm, which replicates the development of some living organisms, was used to fabricate the structure, which features some sections that would have been too fragile to make with concrete or sandstone.

Topology optimization, which allows for designers to take advantage of the geometrical freedoms made possible through additive manufacturing, also came into play in the DBT group’s creative process.

“Computational techniques such as topology optimisation allow designers to design lightweight parts, but the parts optimised with this technique are often difficult to manufacture through traditional methods.

“Our proposed fabrication approach doesn’t encounter the same limits as traditional manufacturing methods and can go further with shape optimisation thanks to the ability of 3D printing to print complex moulds that could be used to fabricate more efficient structures,” said Aghaei Meibodi.

Aghaei Meibodi is hopeful that her student group’s new method can one day be applied to a unique, large-scale project.

“With this new approach of casting metal, one can imagine a return of 3D detailing and 3D articulation, perhaps a fusing of ornament and structure,” she said.

“My dream application of it would be in the building envelope and interior structure of large spaces as large-span supporting structures.”

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[Images via Dezeen]