Design an Artificial Hand in One Month. No Pressure. That’s a Hackathon
The first-ever 3DEXPERIENCE World took place in February 2020, hosted by Nashville, Tennessee. The traditional SOLIDWORKS World format was altered to include other Dassault brands, and with that, several additional competitions and experiences for all those in attendance. A few of the new experiences included the Magic Wheelchair, the 3DEXPERIENCE for Good Hackathon and two build days where attendees could assemble prosthetic hands, or robot kits that will go to students around the country through the Every Kid Gets A Robot initiative by STEAM Connection.
I had the pleasure to join a team in the 3DEXPERIENCE for Good Hackathon, and this is my story of how Team Prosthetic ARMada developed our design and prototype. Before getting into the design, I’ll share some background into the rules of the competition and how it was setup.
Five teams comprised of engineers, students, SOLIDWORKS employees and industrial designers from around the globe collaborates on designing the next generation prosthesis for the Ellen Meadows Prosthetic Hand Foundation (See Image 2).
Image 2. The LN-4 Prosthetic Hand.
My team contained members from the USA, Canada, the United Kingdom and Italy. We called ourselves Team Prosthetic ARMada (see Image 3). Teams had one month to do all conceptualization, design, project management, presentation preparation and prototyping—all using the 3DEXPERIENCE platform. Teams had a limit of working on the project for 30 hours per week, or 120 hours for the entire project.
Image 3. Team Prosthetic ARMada.
The Ellen Meadows Prosthetic HandFoundation was founded in 2005 with the mission to distribute prosthetics to those most in need in the world, at no cost to the end recipient. Since its inception, the foundation has distributed more than 56,000 prosthetic hands to people in over 80 countries, mostly in developing nations in Africa, Southeast Asia and India. There are over 12 million people affected by lower arm amputations worldwide and the foundation’s founder, Michael Mendonca, stated that they would love to distribute 1 million prosthetics.
The Design Criteria
There had to be boundaries on a competition that only lasts one month, but that doesn’t mean there would be compromises to design and ingenuity. Teams received a document with around 30 design requirements, including:
- Design must be manufacturable for under $100.
- Prosthetic should be able to be easily attached.
- Prosthetic should be ambidextrous.
- Prosthetic should be able to lift up to 20 pounds without coming off the recipient’s arm.
- Prosthetic should look more like a human hand than the current design.
- Design must be rugged and be able to get dirt and grime on it (many recipients work in agricultural fields).
- There should be multiple colors available to closely resemble various skin tones.
- Prosthetic should hold everyday objects (pen, cell phone, broom, hair brush, etc.).
Team ARMada’s Design
With such a short timeframe to get a design completed and agreed upon by the team, there was no time to waste at the beginning when doing as much research as would normally be needed for a product such as this. After all, nobody on the team had a background in prosthetics and the time to research would have benefited everyone prior to going into this project.
As a team, we decided to hit the drawing board right away and broke the project down into three main parts:
- How will the prosthetic attach to the arm?
- How will the fingers and thumb work together?
- What will the palm or hand look like?
We decided right away that we wanted to focus on the aesthetics of the prosthetic after we heard that some amputees would use a non-functioning wooden hand rather than the current LN-4 design, since it did not look like a real hand.
Our team came up with many sketches and preliminary designs (see Image 4) on these three design aspects before landing on a direction, which we all originally thought was risky—using compliant mechanisms for the fingers. Compliant mechanisms gave us the flexibility to have a single hand lock a finger into place, and then also release a finger without the use of another hand. This was particularly attractive for double amputees.
Image 4. Prosthetic hand concepts.
With the team choosing to use compliant mechanisms, there were a lot of design iterations that were done to hone in on a working prototype. Instead of sticking with just plastic parts, we used wire-infused plastic to provide much better durability in the joints that move (see Images 5 and 6). This ensured that the overall durability of those heavily-used joints would last for a long time, which was one of the design requirements.
Image 5. Finger Prototype, opened and closed.
Image 6. Finger with wire infused.
The palm component was the next major design task to tackle. We wanted the hand to look realistic, so we used xShape to get an organic shape for the hand (see Image 7). When we put the palm and fingers together, we could get an idea of what our creation would look like (see Image 8).
Image 7. Palm Design in xShape.
Image 8. Palm and fingers together.
Now that the palm and finger designs were complete, we needed to make the fingers look more realistic, so our effort was placed on making “finger coverings.” This task was difficult, with a lot of effort going into designing the coverings to have as few unique parts as possible. With the deadline approaching, and a few days before traveling to Nashville for the conference, one of our team members worked feverishly on the coverings. The night before landing, they had been completed and we could put together our presentation for the audience and judges (See Image 9).
Image 9. Rendering of completed prosthetic hand with finger coverings, thumb and palm assembled.
We knew we were going to do a formal presentation to explain our design and the thought process that had gone into it, but what is better than having a working prototype to demonstrate your design?
One of our team members put a lot of effort into 3D printing our prototype over the last several days before flying to Nashville—and it was a thing of beauty. With the compliant mechanism fingers and thumb, and a very basic palm, we were able to have a working hand that could do many of the day-to-day activities that were required for the competition (See Image 10).
Image 10. Working prosthetic compliant mechanism prototype.
Even though Team Prosthetic ARMada did not come in first place, this was a fantastic opportunity to help give back to the world in a small way. Every person on each team showed great passion and ingenuity in how they tackled the problems presented. After the competition, the winning team has been moving forward with their design and manufacturing, working with the foundation. And, who knows, maybe one day we will be seeing Team Prosthetic ARMada’s design as a next-next generation prosthetic?
To learn more about SOLIDWORKS simulation for product development in health care, check out the whitepaper Simulating for Better Health.
Image 11. All teams for the 3DEXPERIENCE for Good Hackathon.