Senior Mechanical Engineer, Machine Design

Senior Mechanical Engineer, Machine Design Location: San Diego, CA Job Type: Full-Time $130,000 - $140,000 Machine Design - Own the design of precision mechanical systems including frames, motion elements, fixtures, and actuation mechanisms - Perform tolerance stack-ups and define GD&T for precision assemblies - Develop and manage mechanical error budgets (alignment, motion accuracy). - Analyze stiffness, deflection, vibration, and fatigue using analytical methods and FEA - Design mechanisms that balance performance, cost, manufacturability, and reliability Thermal Control Hardware - Design thermal control systems including heaters, heat exchangers, insulation, cold plates, airflow systems, and structural thermal paths - Translate temperature stability and uniformity requirements into hardware specifications - Perform thermal modeling and first-principles heat transfer calculations (conduction, convection, radiation) - Develop and maintain thermal error budgets (drift, gradients, response time) - Collaborate with electrical and firmware engineers on sensor placement and control strategy integration Fluid Control Hardware Design - Design fluid handling assemblies including manifolds, tubing routing, fittings, valves, pumps, and reservoirs - Perform flow calculations (pressure drop, flow rate, Reynolds number) - Support material selection for chemical compatibility and biocompatibility - Integrate fluidic subsystems with thermal and mechanical assemblies - Develop leak testing and validation strategies Analysis & Validation - Build structured analytical models to predict mechanical, thermal, and fluidic performance - Maintain subsystem-level error budgets (mechanical, thermal stability, flow accuracy) - Design and execute validation testing for temperature stability, fluid accuracy, drift, and mechanical robustness - Perform structured root cause analysis when performance targets are not met - Support DFMEA and risk assessment activities Prototyping & Integration - Assemble and debug mechanical, thermal, and fluidic prototypes - Instrument systems for temperature, flow, and mechanical performance measurement - Iterate quickly based on test results and integration feedback - Support alpha and beta system builds Manufacturing & Documentation - Create detailed mechanical drawings with proper GD&T - Participate in DFM/DFA reviews - Work with vendors on machined, sheet metal, molded, and fluidic components - Support transition from prototype to low-volume production Qualifications Required - B.S. or M.S. in Mechanical Engineering or related field - 5–8+ years of experience in precision machine design, thermal systems, and/or fluid handling hardware - Strong foundation in tolerance analysis and error budgeting - Experience performing thermal and fluid flow calculations - Proficiency in 3D CAD (e.g. SolidWorks) - Hands-on experience building and testing hardware Preferred - Experience in bioinstrumentation, medical devices, diagnostics, or scientific equipment - Experience designing closed-loop temperature-controlled systems - Experience with microfluidic or low-volume reagent handling systems - Familiarity with FEA tools for structural and thermal analysis - Experience selecting materials for chemical compatibility - Experience supporting early-stage production builds What We’re Looking For - Analytical thinker who quantifies performance limits and tradeoffs - Strong mechanical fundamentals with systems-level intuition - Comfortable owning subsystems end-to-end - Hands-on builder who enjoys working in the lab - Clear communicator across electrical, firmware, fluidics, and systems teams We are an equal opportunity employer. We thrive on diversity and collaboration.