Prosthetic limbs can come in many shapes and sizes; from the classic pirate’s hook, to Anakin Skywalker’s mechno-arm and Jaime Lannister’s solid gold hand.
In 2017, David Aguilar (Andorra), aka "Hand Solo", created the world’s first functional LEGO® prosthetic arm.
Named MK-I (Mark 1), after the suit built by comic-book hero Iron Man, it’s movement was purely mechanical. After much refinement, David’s latest MK-V LEGO® prosthetic arm is motorized, with five fingers that he controls by making subtle movements of his residual arm.
David is on a one man – and one hand – mission to make his LEGO® prosthetic arms widely available to all those in need.
David was born without a right forearm due to Poland Syndrome, a congenital disease that also prevented his right pectoral muscle from developing.
Being different to all the other children made David nervous, but it didn't knock his confidence. Instead, it fuelled his dreams.
"I wanted to … see myself in the mirror like I see other guys, with two hands."
David began designing prosthetic arms from the age of nine and decided to build them with the material he knew best.
"LEGO® was my first toy as a kid, it felt that you could build an infinite amount of things. Imagination was the only limit!"
Nine years later, aged 18, David designed the MK-I using bricks from a LEGO® Technic helicopter set. It featured a moveable elbow joint and a grabber for picking things up, which he activated by bending his elbow.
"My first model isn't motorized, I control it with my muscles and it becomes a bit painful once you spend a long time with it. Good thing is, the MK-I is strong enough to support my weight when performing some push-ups!"
David’s most recent model, the MK-V, carries a Spike Prime Hub – a programmable control unit capable of receiving and sending orders from sensors to motors.
"It's the most comfortable prosthetic of my models and I don't need to use my muscles to lift something. The servo motors do it for me!"
After revealing it at an event held by NASA, David was dubbed "the real-life Tony Stark" by Charlie Wen, who founded and heads up Marvel's Visual Development department alongside Ryan Meinerding.
The main challenge David faces when building prosthetic arms is balancing functionality and comfort.
"You can't wear something very uncomfortable, even if it's super functional, and vice-versa."
If you’ve ever felt the pain of stepping on stray LEGO® bricks, you may cast aspersions at the idea of intentionally wearing them. However, some of the pieces are round or curved enough to be smooth against skin.
Building LEGO® prostheses for others
Ordinary prosthetic limbs can be expensive, especially when factoring in maintenance and replacement parts. The high costs are prohibitive for many people.
David is a bioengineering student and his goal in life is to make prosthetic arms that are affordable and accessible worldwide.
The news of his Guinness World Records title reached the parents of Beknur, an 8-year-old boy who doesn’t have developed limbs.
They contacted David and asked for a LEGO® prosthesis for their son, to help improve his autonomy. Upon hearing Beknur's story, David decided to make not just one prosthetic arm, but two!
Beknur and his mother traveled 1,300 kilometers, from their home in Strasbourg, France, to Andorra to receive the prosthetic arms from David.
It didn’t take long for little Beknur to master his new arms. He can now pick up items with the MK-Beknur and use a tablet with the eMK-Beknur.
It cost David just €15 ($18) to make them.
"With Beknur's case, I felt an immense joy and happiness when I saw him moving the LEGO® prosthetic for the first time. He was smiling so hard it was contagious! I feel like if I'm lucky enough to keep building these prosthetics, I can help more children and people around the world."
David provides free instructions on how to build the MK-V LEGO® prosthetic arm on his YouTube channel Hand Solo.
David has big plans for the MK-VI and beyond
David has lots of ideas for future prosthetic arms.
His main goal for the the MK-VI is to be able to move the hand and elbow independently. He’s also planning to build different versions of the existing fingers, to achieve a more natural movement.
The idea of using materials other than LEGO® also excites David.
"I'm thinking about 3D printing PLA or FLEX, honestly that would be a game changer for my prosthetics!"
One of David’s biggest inspirations is his father, who always supported David’s dreams.
The proud dad brought media attention to David's story by posting the first video of the MK-I online. The pair have co-written a book, titled Piece by Piece (Pieza a Pieza), which documents their journey together.
"I would have loved that he had been the recipient of an award for his efforts in helping me to be a normal child like the others."
David is also telling his story through educational comics for kids and an upcoming documentary, titled MR. HAND SOLO.
David's Guinness World Records title was just the beginning - he plans to build more prosthetics, inspire more people and keep helping those in need. He hopes to make the world a more friendly, accepting and tolerant place to live in.
"Now, children around the world will learn about my story, and hopefully will change the way they think when looking at someone else that doesn't look like them, doesn't matter if they are missing a limb, they have Down Syndrome, autism... Everyone's different, and that's what makes us unique!"