The Role

Apptronik is seeking a Principal Mechanical Engineer – Structural Simulation to serve as the technical authority for the structural integrity, mass optimization, and dynamic performance of our humanoid robot, Apollo. In this role, you will lead the simulation strategy that allows us to move from "concept" to "validated hardware" with minimal physical prototyping cycles.

As a Principal Engineer, you aren't just running FEA; you are defining the simulation architecture. You will tackle the most complex physics problems—impact dynamics, high-cycle fatigue in high-DOF joints, and multi-body dynamics—ensuring that every gram of material on the robot is earning its keep. You will bridge the gap between high-level autonomous behaviors and the physical limits of the machine's skeleton.

Responsibilities

• Simulation Roadmap: Define the software toolchain and methodology to be used across the mechanical engineering team.
• Predictive Engineering: Shift the culture from "design and then check" to "simulation-driven design," where analysis informs the initial architectural trade-offs of the robot.
• Standardization: Develop company-wide standards for material models, boundary conditions, and safety factors for humanoid-specific load cases (e.g., falls, high-speed walking, and heavy lifting).
• Non-Linear & Dynamic FEA: Lead the analysis of complex, non-linear events such as high-velocity impacts (robot falls) and transient dynamic loads during rapid limb acceleration.
• Fatigue & Life Prediction: Own the fatigue life models for the robot’s primary structure. Predict the lifecycle of components subjected to millions of gait cycles using advanced fracture mechanics and durability analysis.
• Mass Optimization: Utilize topology optimization and generative design to drive aggressive mass reduction across the limbs and torso while maintaining required stiffness-to-weight ratios.
• Test/Sim Correlation: Work closely with the Hardware Integration and Test team to design physical experiments (strain gauging, modal testing, drop tests) that validate and "tune" your simulation models.
• Material Characterization: Lead the efforts to characterize specialized materials—from high-strength aerospace alloys to advanced composites and 3D-printed lattices—to ensure accurate simulation inputs.
• Mentorship: Act as the primary technical mentor for senior and staff-level engineers, providing "deep-dive" design reviews and solving the "impossible" physics bottlenecks.

Qualifications

• Experience: 15+ years of experience in structural simulation and mechanical design, with a proven track record of shipping complex, high-performance electromechanical products (Robotics, Aerospace, or Automotive).
• Software Mastery: Expert-level proficiency in industry-standard simulation suites (e.g., Ansys, Abaqus, SimCenter).
• Physics Depth: Deep mastery of solid mechanics, vibration (vibration, shock, and modal analysis), heat transfer, and multi-body dynamics.
• Humanoid Context: Specific experience with high-speed moving mechanisms or "lightweighting" structures for mobile platforms is highly preferred.

Education: PhD or MS in Mechanical Engineering, Aerospace Engineering, or a related field with a focus on Computational Mechanics.