He Built His First Prosthetic Arm From LEGO at Age Nine

When David Aguilar was nine years old, LEGO was more than a childhood toy. For the boy from Andorra, it became the starting point for an idea that would eventually change his life.

Aguilar was born without the lower part of his right arm because of Poland syndrome. During childhood, he was sometimes bullied because of his physical difference. He often escaped to his room and spent hours building things with LEGO.

One day, he decided to try something different. Using LEGO pieces, he built a simple model that could be placed over his arm. It was not strong enough to function as a practical prosthesis, but it showed him that his idea could work.

He continued experimenting for years. At 18, Aguilar created a fully functional mechanical prosthetic arm using LEGO Technic components. He called the design the MK-I.

The invention eventually earned him a Guinness World Records title for creating the first functional LEGO prosthetic arm. He later developed more advanced versions, including a motorized model with five fingers.

What began as a way to overcome his own challenges gradually became something bigger. Aguilar began designing prosthetic devices for other people, including children who were born with underdeveloped limbs.

Guinness World Records describes Aguilar as an inventor who continues to use his engineering skills to promote inclusion and innovation. He has also studied bioengineering, combining his childhood passion for building with his interest in technology.

His story has continued to attract international attention because the invention was not created in a conventional laboratory. It grew from a child’s curiosity, years of experimentation and a determination to find a practical solution to a personal challenge.

For Aguilar, the LEGO arm became more than a record-breaking invention. It became a way to show that creative ideas can help people see physical differences in a different light — and potentially help others facing similar challenges.

Sources: BBC World Service, Outlook; Guinness World Records.