
Video screenshot via Guinness World Records
For David Aguilar, LEGO was never just a toy—it was the foundation for a future filled with possibility. The bioengineering graduate, nicknamed “Hand Solo,” first made headlines when he built the world’s first functional LEGO prosthetic arm at 18, earning a Guinness World Record in 2017. His passion for using LEGO to make prosthetics more accessible didn’t stop there. In 2021, Aguilar extended his work to help eight-year-old Beknur Zhanibekuly, a boy from Strasbourg, France, born with underdeveloped limbs.
After hearing about Aguilar’s record-breaking designs, Beknur’s parents reached out in hopes that he could craft a prosthetic suited to their son’s needs. Traditional artificial limbs were not an option due to Beknur’s small limb size, but Aguilar saw an opportunity to create something customized.

Video screenshot via Guinness World Records
Using LEGO bricks, he built a prosthetic arm that not only functioned but also allowed Beknur to engage in everyday tasks with greater independence.
Beknur watched eagerly as Aguilar conceptualized the prosthetic. When asked if he was satisfied with the colors, he gleefully remarked, “I think they look perfect!”
Once the device was completed, the boy wasted no time testing out his new arm, quickly mastering its movement. Aguilar, witnessing the excitement firsthand, described the experience as an “immense joy and happiness,” especially seeing Beknur’s beaming smile as he moved the prosthetic for the first time.

Video screenshot via Guinness World Records
“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,” Aguilar reflected.

Video screenshot via Guinness World Records
The Guinness World Records, which documented the experience back in 2021, has recounted the sweet exchange once again for a new audience on social media.
The design, named ‘eMK-Beknur’, included a grappling pincer controlled by a cord attached to one foot, allowing for intuitive movement.
One of the most impressive aspects of the LEGO prosthetic is its affordability. While traditional prosthetic limbs can be prohibitively expensive, Aguilar’s design cost just €15 (US$18) to build.
Aguilar’s innovative work continued to break barriers in prosthetic design. The low-cost ‘eMK-Beknur’ model set two Guinness World Records in 2021: the first functional foot-controlled LEGO prosthetic arm and the first functional LEGO prosthetic arm with a stylus.
The mission of “Hand Solo” remains the same—to make prosthetics more accessible, one LEGO brick at a time.
[via Guinness World Records]