Polish Designer Uses Sinterit Lisa 3D Printer to Make Exoskeleton Arms for Children with Spinal Muscular Atrophy

I’ve heard it said that a kid’s main job is just to be a kid – go play, and enjoy the time before adult problems start crowding in. However, I imagine it’s pretty tough to just be a kid when you have a genetic neuromuscular disease like Spinal Muscular Atrophy (SMA), which means that you can’t move your arms, hands, or legs without the use of special external supportive devices. The inherited disease affects the nerves that are responsible for muscle functions. But thanks to the innovative 3D printing technology that’s available today, kids with SMA and similar diseases have a better chance of focusing on being kids. We’ve seen personal robots that assist people with mobility issues, assistive prosthetic devices, and 3D printed exoskeletons for kids. Poland-based Sinterit, the first producer in the world of an affordable desktop SLS 3D printer, recently worked with a 3D designer to develop a 3D printed exoskeleton arm for kids with SMA.

The company, made up of ex-Google employees, was founded in late 2014, and not long after introduced the award-winning Sinterit Lisa, a plug and play SLS 3D printer with high precision and no need to print with supports. Sinterit’s mission is to provide professional, cost-effective SLS (selective laser sintering) 3D printers – the technique can create precise, internally complex shapes, which helps lower the number of required parts for objects like exoskeletons, making them more comfortable to wear. The company recently introduced an automated powder sieve to go with the Lisa 3D printer, which makes the printing process easier and more effective; the sieve also recycles the printing powder. 3D printed parts produced by the Lisa are lightweight and durable, an important consideration for projects like kid-friendly exoskeleton arms.

Sinterit’s 3D printed exoskeleton arm gives children with SMA a way to improve their quality of life by increasing their motor skills, so they’re able to move their hands, play, draw, and generally go about the business of being a kid.

The project began with a phone call: the mother of a three-year-old boy named Radek, who has SMA, called 3D designer Bartłomiej Gaczorek, from Crystal Cave Sp. z o. o. The boy had previously tested some other 3D printed assistive devices, but the low-cost alternatives were not a good fit for him. His mother hadn’t found any other solutions, and knowing that Gaczorek had 3D experience, asked him for help.

Gaczorek agreed, and began to work on his exoskeleton design. After doing some research, he determined that while some of the existing 3D printed exoskeletons are well-engineered, they could do with some improvements.

The goal was clear – design and create an inexpensive, easy to use, dynamic support exoskeleton arm for kids, able to be used immediately out of the box. Through each phase of the project, Gaczorek consulted with doctors, physiotherapists, and other parents of children with SMA, who understand the individual needs of these children.

While determining which 3D printing process to go with, Gaczorek considered FDM and SLA, but ultimately decided that SLS 3D printing was the best choice, due to its freedom of form, strong yet lightweight material, and printing precision; all of these features are important in terms of making unique, complex exoskeleton parts, and in preparing the first prototypes. He then decided to go with the Sinterit Lisa 3D printer for the project.

“I decided to print main elements in SLS technology, because it has complex internal structure. In other technology like FDM you would not maintain the required precision and tolerance (0,05mm) demanded for work with bearing,” said Gaczorek. “Additionally printing with FDM requires supports and its removing is time-consuming. Another thing is the comfort of user which is much better with SLS/SLA technology. The cost of Sinterit Lisa SLS printing is already very low compared to other industrial machines and the quality is perfect.”

Gaczorek used Autodesk Fusion 360 software to design the exoskeleton, as it makes shape optimization and complex movement analysis possible, and used non-toxic, high-strength materials to 3D print the complex parts of the exoskeleton. SLS 3D printing was able to deliver the proper amount of precision for the project, which is necessary for the parts to work well with the exoskeleton bearings.

Comfort was also a key factor for Gaczorek to consider while designing the exoskeleton, which helped to determine its “sleek look,” and was another of the several reasons he chose to go with SLS. Thanks to 3D printing technology, the design, development, and testing stages of the exoskeleton took far less time than if traditional manufacturing methods had been used, which means that Radek and other children with SMA can potentially receive 3D printed exoskeleton arms without having to wait too long.

Gaczorek and Sinterit are continuing to work together to develop 3D printed exoskeletons for three more children in Poland with SMA. You can read Sinterit’s case study for this exoskeleton project here. Discuss in the Sinterit forum at 3DPB.com.