Scientists have created MUSBRIC, a modular platform that lets researchers build and swap out reconfigurable musculoskeletal robots quickly. By attaching LEGO‑compatible endcaps to fiber‑reinforced pulsating muscles, the system turns each muscle into a reusable, plug‑and‑play brick that fits directly onto standard LEGO pieces.

In an elbow‑joint prototype, researchers found that routing the triceps muscle through a pulley keeps the moment arm steady while the joint moves. Direct attachment, without the pulley, makes the moment arm flip sign and stops the robot from extending fully. The experiments measured joint angles under 0, 50, and 100‑gram loads, showing the pulley design yields smooth flexion and extension in both directions.

A robotic hand built with the same bricks demonstrated compliant grasping and could move multiple joints. The team also built a quadruped robot, testing only one simple open‑loop gait.

While the simulated muscle dynamics are quasi‑static and add a simple damping term, and the hand limits how many joints can be controlled independently, the platform still offers a low‑cost, highly modular approach to testing different robot designs. Future work will expand the range of controlled joints and add more advanced control strategies.

Visuals: • Fig. 3 – shows the elbow joint with pulley‑guided routing and experimental joint responses under different loads.