California Institute of Technology

The California Institute of Technology in Pasadena is a private research university founded in 1891. Its legged-robot work sits in the Center for Autonomous Systems and Technologies (CAST), endowed by Foster and Coco Stanback, and in the AMBER Lab of Aaron Ames, who directs CAST and is known for control barrier functions, a method for formal safety guarantees on legged robots.

Caltech's one named humanoid-type robot is LEONARDO, a 2.5 foot biped with two three-joint legs and four propeller thrusters at its shoulders, developed by Soon-Jo Chung's group with Kyunam Kim and Patrick Spieler and funded by the Gary Clinard Innovation Fund and CAST. It was the October 2021 cover story in Science Robotics after walking a slackline and riding a skateboard by balancing with its thrusters. It is a research prototype; the stated follow-on goal was legged landing gear for Mars rotorcraft, not a humanoid.

Since then Caltech has used commercial humanoids as platforms instead of building its own. In October 2025 the Ames and Gharib groups, with the Technology Innovation Institute of Abu Dhabi, demonstrated a modified Unitree G1 carrying Caltech's M4 flying and driving robot as a backpack across campus in a mock emergency response. The value is in the control theory, not hardware, and nothing has been commercialised.