Staff Mechanical Engineer - Tech Lead

Apptronik is a human-centered robotics company developing AI-powered robots to support humanity in every facet of life. Our flagship humanoid robot, Apollo, is built to collaborate thoughtfully with people, starting with critical industries such as manufacturing and logistics, with future applications in healthcare, the home, and beyond. We operate at the cutting edge of embodied AI, applying our expertise across the full robotics stack to solve some of society's most important problems. You will join a team dedicated to bringing Apollo to market at scale, tackling the complex challenges like safety, commercialization, and mass production to change the world for the better.

JOB SUMMARY

Apptronik is seeking a Staff Mechanical Engineer to serve as the technical lead for Apollo’s lower body. This is a high-visibility leadership role responsible for the hip, leg, knee, ankle, and foot assemblies.

You will own the complete lifecycle—architecture, design, integration, and verification—of the lower body stack. This position requires deep expertise in locomotion kinematics, dynamic stability, and high-load structural design. You will lead the development of systems that must deliver human-like mobility, absorb high-energy impacts, and maintain durability across millions of cycles in real-world environments.

ESSENTIAL DUTIES AND RESPONSIBILITIES or KEY ACCOUNTABILITIES

System Architecture & Locomotion Design

• Lower Body Ownership: Define the mechanical architecture for the hips, legs, knees, ankles, and feet. Lead trade-off studies between power density, range of motion (ROM), stability, and energy efficiency.
• Locomotion Performance: Architect systems that enable stable walking, running, lifting, and recovery from disturbances (e.g., slips, trips, and falls). Balance dynamic performance with robustness and safety.
• Mass Distribution & Stability: Optimize mass placement and inertia to improve balance, agility, and whole-body coordination.

Complex Mechanism Design

• High-Performance Joints: Drive the design of multi-DOF joints (hip, knee, ankle) capable of high torque output and high cycle life while maintaining precision and backdrivability where needed.
• Shock & Impact Management: Design structures and mechanisms that absorb and dissipate energy during foot-ground contact and high-impact events (e.g., stepping off ledges, falls).
• Structural Integrity: Lead the design of the lower body load path to support full robot mass and dynamic loads using advanced materials and topology optimization.

Ground Interface & Mobility

• Foot & Contact Design: Develop feet and contact interfaces that provide traction, compliance, and adaptability across varied terrains.
• Actuation Integration: Partner closely with controls and actuation teams to ensure mechanical designs support force control, impedance