Senior Actuation Engineer (Humanoid Joints)

Location: Shanghai, China

Company

Developing AI-first humanoid robots that combine perception, reasoning, dexterous manipulation, and continuous learning.

What you will do

• Design high-torque-density actuator modules for humanoid legs, waist, and arms using quasi-direct-drive architectures with planetary reduction.
• Own motor selection, gear design, bearings, sealing, packaging, sensing integration, and joint torque, speed, thermal, and mass budgets.
• Collaborate with motion control, electrical, and embedded teams on transmission trade-offs and motor-controller integration.
• Design surrounding mechanical structures, including limbs, torso frames, and brackets, for rapid prototype fabrication.
• Take designs from concept through CAD, tolerance analysis, DFM, fabrication, and supplier follow-up.
• Run joint-level dynamometer and life testing, then iterate designs using test data.

Requirements

• Bachelor’s or master’s degree in Mechanical Engineering or Mechatronics.
• 8+ years of experience designing electromechanical actuation systems with BLDC motors and planetary reduction, ideally in quasi-direct-drive configurations.
• Deep understanding of motor physics, including torque constants, saturation, thermal limits, and transmission selection.
• Strong CAD skills in SolidWorks, NX, or Creo, with a proven concept-to-hardware track record.
• Experience with structural design, materials selection, prototype fabrication, and rotating-machinery testing.
• Ability to work hands-on in a lab and iterate effectively in a fast-changing environment.

Nice to have

• Experience designing humanoid or quadruped joint modules.
• Gear design experience, supplier coordination, or custom motor-winding specification.
• Experience optimizing proprioceptive actuation and backdrivability.
• Thermal simulation and FEA experience.
• Ability to communicate technical topics in English with international teams.

Culture & Benefits

• Work in a small, senior, hands-on robotics engineering team.
• Focus on rapid iteration and first-principles engineering.
• Collaborate with engineering teams at headquarters on a next-generation full-size humanoid platform.
• Workplace: on-site in Shanghai, China.