Several years ago, the arrival of low-cost desktop 3D printers generated the much-hyped concept that every household would own a 3D printer, with which they would fabricate custom goods on demand. The hype bubble surrounding consumer 3D printing has since burst, but, in its wake, researchers and companies have been able to make real progress in improving desktop 3D printing technology. In fact, we are closer than ever before to bringing a 3D printer to every home.

The 3D printer that all of us may own does not resemble the thermoplastic extrusion devices that emerged on the market a few years back. Actually, you are most likely carrying the major hardware components for this printer around in your pocket or handbag. That's because this 3D printer uses an ordinary smartphone to print objects with visible light.

The T3D 3D printer uses visible light to print objects from photopolymer resin. (Image courtesy of Taiwan 3D Tech.)

Unveiled at CES this year was the T3D, the first smartphone 3D printer from Taiwan. To understand how it works, I spoke with Sung YiChun, founder of Taiwan 3D Tech, who was able to shed light on 3D printing with visible light.

3D Printing with Your Smartphone

I met one of the pioneers of smartphone 3D printing in Taiwan in 2015. Jeng Ywam Jeng, professor of Mechanical Engineering and dean of the College of Engineering at National Taiwan University of Science and Technology (Taiwan Tech), and his students were in the process of polishing a final prototype device. Even at that early stage, it was impressive.

“This original concept was conceived of in 2012 by Professor Jeng,” said Sung. “He believes that mobile devices will eventually replace the PC as an indispensable part of our lives. Based on his experience and knowledge in the 3D printing field, he proposed a feasible project to replace the expensive optical system typically used with a mobile phone instead. He said a mobile phone is the most popular and simple digital light masking system for a DLP 3D printer.”

As with all 3D printing processes, Digital Light Processing(DLP) 3D printing begins with a 3D model, which is sliced into individual layers. Each layer is then cast by a light source onto a vat of photopolymer resin, solidifying the liquid plastic layer by layer. Typically, this light source is a DLP projector, like you might buy from a consumer electronics store, shining near-UV light. In the case of T3D’s 3D printer, it is the screen on a smartphone.

“Indeed, that was an unprecedented and amazing idea,” Sung continued. “After few years, this idea has been realized in the 3D printing laboratories at NTUST. In 2014, the first time I met Prof Jeng, he was very excited to tell me these remarkable results. We decided to turn this research project together into commercialization.”

They key to this process, according to Sung, is the resin itself. Photopolymers are thermosets, plastics that cannot be remelted, that are sensitive to light. Key to their composition are photoinitiators, oligomers and/or monomers. Once hit with light, photoinitiators convert light into chemical energy and cause the mixture of oligomers and monomers to form three-dimensional polymer networks. Other ingredients, such as epoxies, urethanes and polyesters might also be added to the chemistry to change the physical properties of the material, to make it stiffer or more viscous. Fillers, pigments and other materials may alter the color or other physical properties, as well.

A 3D-printed object made with multiple different colored resins using the T3D printer. (Image courtesy of Taiwan 3D Tech.)

In the case of the resin for the T3D, Taiwan 3D Tech has specially engineered a resin that hardens in response to light within the visible range, rather than near-UV range. “Our resin is mixed with a combination of different types of monomers. After visible light exposure, the special resin will solidify through the reaction of polymerization. This is what makes T3D comparatively different from traditional 3D printers,” Sung said.

“The visible light-cured resin reacts to specific electromagnetic spectrum ranges, included in the visible light wavelengths from 400 to 700 nm,” he continued. “As an example, it is very similar to dental fillings (tooth-colored fillings) used with a dental curing light. We have made the necessary modifications to the composition of the resin to increase the sensitivity and accuracy to make sure it is suitable to work with smartphone/tablet displays.”

One question that might come to mind is how this material doesn’t cure when immediately exposed to the light of day. Sung explained, “Our visible light curing resin is not as sensitive as film. There is no need to operate in a darkroom. For safety, we do not encourage users to operate in a very dark room. We recommend you keep some light on in the room and lower the brightness with a dimmer, or use a red/orange translucent film to mask the direct light source. Sunlight must be shaded during the whole process. We will provide the recommended illuminance in our operating manual.”

The Specs of the T3D Printer

The T3D 3D printer. (Image courtesy of Taiwan 3D Tech.)

Now that the necessary research has been completed, the T3D is ready for market. The company will be launching a Kickstarter campaign to fund the manufacturing of the devices this year. The goal is to begin delivering them before this autumn.

Because backers likely carry the crucial hardware for this printer in their pockets, Taiwan 3D Tech will be manufacturing the apparatus for lifting prints out of the resin vat, developing the necessary software for performing the fabrication process and creating the resins that can be cured with visible light. Manufacturing should not be difficult, given the simplicity of the system, but, as many have learned from crowdfunding campaigns, things don’t always run as smoothly as one would hope.

For instance, another smartphone 3D printer was funded on Kickstarter earlier this year, but backers are still awaiting delivery due to issues related to safety and quality certification. Fortunately for backers of the T3D, the start-up already has close connections with manufacturers, such as New Kinpo Group, the Taiwanese mega-manufacturer that owns XYZprinting, and which is also one of the most popular desktop 3D printer manufacturers in the world.

“In the past two decades, Professor Jeng has been dedicated to 3D printing education and has always sustained a sound and active relationship with the 3D printing industry,” Sung said. “XYZprinting is definitely one of our important partners and will play a critical role in 3D printer manufacturing in the future. At the same time, T3D will focus on the research and development of our proprietary light-sensitive resin to ensure compatibility and quality.”

When it does hit the market, the surface area of the T3D 3D printer will about 5.8 inches in size. This is actually larger than most typical smartphones. That’s because the T3D 3D printer is not designed with only smartphones in mind, but can actually work with a tablet, as well, meaning that the build volume of the T3D 3D printer is scalable. One can even imagine the same technology extrapolated to even larger displays.

“The standard exposure time for a 0.1 mm layer is between 20 and 30 seconds, depending on the device and resin,” Sung said. “The total print time depends on the height of the object, and the print speed is between 1 and 1.3 cm per hour.”

The Future of Smartphone 3D Printing

When it launches, the T3D 3D printer will already be a useful prototyping tool. As is the case with a traditional DLP system, it will be possible to create plastic models of CAD designs. The difference is that this printer will cost only $249, meaning that just about any engineer should be able to afford one.

A 3D-printed model from the T3D 3D printer. (Image courtesy of Taiwan 3D Tech.)

As other desktop brands have already demonstrated, low-cost 3D printing is becoming an essential tool in the design process. It serves as a means for iterating physical objects very early on before using more costly 3D printers for further prototyping or heading to mass manufacturing. With such an accessible 3D printer as one that uses an ordinary smartphone, there’s no reason that every engineer won’t begin prototyping designs. For dental and medical labs, castable and clear resins could mean almost instant access to 3D printable crowns and surgical guides—if the resolution of the printer is high enough.

Sung said that the technology will become even more useful as T3D releases more resins. He explained, “In our product development roadmap, we plan to introduce additional functional materials to help engineers and designers to realize their creativity in the early stages. And to facilitate this promotion, these materials will be provided at no additional costs for a period of time.”

It’s difficult to determine what the future of 3D printing will look like exactly, but it’s interesting to think about. If the technology becomes powerful enough, every household really might begin 3D printing custom goods on demand.

“We truly believe that 3D printing will change people's lives,” Sung said. “Currently, a small number of people, mainly the Maker community, have already made desktop 3D printing a key part of their lives. However, in terms of the general population, they still need some more time to evaluate and understand this technology.

“As a reference, in the past, it took 15 years for laser printers to move from $3,000+ market pioneer to $200 consumer market. Based on the current pricing of 3D printers, adoption of 3D printing technology should be much faster. Right now is definitely a good time to get more people involved with 3D printing technology,” Sung concluded. “At T3D, we believe 3D printing will change the way you live.”

To learn more about T3D and its technology, visit the company website



