Meet Acroban, a compliant humanoid project being developed by the Inria Flowers Research team in France. This humanoid robot, made mostly from RX-64 Dynamixels from the look of it, is impressive in that it uses a semi-passive dynamic locomotion and reliance on natural backlash compliance (along with structural flex & elastics) to portray some very lifelike movements.

Acroban is a lightweight compliant humanoid robot capable of robust semi-passive dynamic locomotion, life-like movements, and offers the possibility of a new kind of playful physical human-robot interaction. We developped this platform to explore how morphological constraints can simplify the developmental acquisition of complex sensorimotor skills, as well as to explore novel kinds of human-robot interaction.

The video demonstrates this very well, bringing a rather mechanical and utilitarian looking robot to life. Inria Flowers calls this the ‘Luxo Jr. Effect’ named after the pint size companion of Pixar’s lovable Desk Lamp mascot. It really is true though; something about the way this robot moves reaches out to our primal emotional response, making our brain think it’s something actually alive. In doing this, the robot effectively leaps over Uncanny Valley by coming across as very human-like without the increasingly creepy aesthetics that many humanoids fall victim to.

The Luxo Jr. Effect

Furthermore, Acroban provokes spontaneous highly positive emotional reactions, especially in children. Yet, as opposed to many other robots, its morphology is neither roundish nor cute. He has no big eyes. He is just made of metal, and its appearance shows it explicitly. At first glance, its visual appearance creates low expectation of intelligence and life-likeness. But when it begins to move and one can touch it, its natural dynamics, much more life-like than most other robots, triggers a high contrast and positive surprise. Life unexpectedly appears out of a neutral metallic object, much as Pixar’s Luxo Jr. This is the Luxo Jr. effect.

Enough talk, check out the demonstration video (especially the interaction with kids later on). If you’re looking for more info, the Acroban Page has a wealth of videos and writing on the project.