When most teenagers build something with LEGO, it’s a castle or a race car. Sixteen-year-old Jared Lepora, from Bristol, built a robotic hand — and not just any hand. His design performs nearly as well as professional research models.
Lepora’s creation, called the Educational SoftHand-A, is a tendon-driven, fully articulated robotic hand inspired by the Pisa/IIT SoftHand, a well-known research platform used in soft robotics. The difference? His version was made entirely from standard LEGO MINDSTORMS parts, using only components that anyone could buy off the shelf.
Soft Robotics Meets LEGO
The Educational SoftHand-A uses a pair of motors to pull tendons that act like muscles, allowing the fingers to flex and extend in lifelike ways. Each finger is equipped with agonist and antagonist tendons, mimicking how human muscles work in opposition to move a joint.
Even more impressively, the hand uses LEGO clutch gears to achieve what researchers call soft synergies — a principle that allows the fingers to adapt their movement based on the shape of the object being grasped. This gives the hand the ability to gently wrap around a cup, press against a ball, or hold a shoe, all without complex programming.
The result is a lightweight, adaptive robotic hand that can perform human-like grasps using nothing more than LEGO parts and a few small servo motors.
Almost Research-Grade Performance
In testing, Lepora’s LEGO hand matched many of the functional benchmarks of the lab-grade SoftHand-A used in university research. Each finger can lift up to 6 newtons of force and close in roughly one second. That’s about half the speed of professional 3D-printed models, but remarkably close given the materials.
The entire system is powered by the LEGO MINDSTORMS EV3 controller, with sensors and motors synchronized through a simple tendon-driven differential mechanism.
Engineering That Inspires
What makes this story stand out isn’t just the technical execution — it’s the accessibility. By building a research-level robotic hand with LEGO, Lepora has created a hands-on learning tool that could help students around the world understand soft robotics, tendon actuation, and biomimetic design.
It’s proof that innovation doesn’t always require a university lab or specialized tools. Sometimes, it just takes creativity, persistence, and a box of plastic bricks.
The work, co-authored with researchers from the University of Bristol and the Bristol Robotics Laboratory, was published in arXiv (October 2025) and shows how soft robotic design principles can be translated into educational platforms that spark curiosity as well as technical skill.
Read the full paper: [2510.15638] Educational SoftHand-A: Building an Anthropomorphic Hand with Soft Synergies using LEGO MINDSTORMS
