Mechanical Design Engineer, Thermal and Portable Hardware

Thalraen is a Bay Area hardware startup building HydraBox, a portable, solar-powered device that pulls drinking water out of the air, including dry air where condensation-only systems struggle. We're a small, founder-led team, preparing an NSF SBIR Phase I proposal on a sorbent-based approach.

Pay: $7,000/month (about $50/hour) plus 1% equity. Part-time, fixed-term W-2: 32 hours/week for 7 months, on-site in the SF Bay Area.

This position is contingent on Thalraen receiving an NSF SBIR Phase I award. We expect work to begin around May 2027 if awarded. An award is not guaranteed.

The role

You'll design how everything fits and works together: the enclosure, the thermal path, the water path, and the mounts for MOF sorbent plates, resistive heating, fans, battery and electronics, all inside a weight budget a person can carry. You'll work with the founder and the sorption engineer, build what you draw at a local makerspace, and iterate fast. Seven months, a small team, and your design decisions ship.

What you'll do

• Own the mechanical architecture of a portable, weight-constrained device: enclosure, internal layout, mounting, serviceability.
• Design the thermal path: pin-fin cold plates, airflow, insulation, and isolation between the heated sorbent plates and the rest of the device.
• Design condensate and water handling: collection, sealing, drainage, and potable-contact material choices.
• Package batteries, wiring, sensors and a small controller board safely.
• Prototype with CNC, 3D printing and sheet metal at bay area labs and makerspaces, designing for manufacture from the start.
• Hold weight, volume and power budgets, and track the mass impact of every change.
• Work with the sorption engineer to iterate bed geometry and fixtures.
• Keep drawings, BOMs and test records that feed NSF Phase I reports.

You're a fit if

• You hold a BS or MS in mechanical engineering or a close field.
• You have 3+ years designing physical products or hardware, from CAD to a built prototype.
• You're fluent in a parametric CAD tool (SolidWorks, Fusion, Onshape or similar) and in drawings and GD&T basics.
• You make your own prototypes: you machine, print or assemble.
• You understand heat transfer in thermal systems or electronics: heatsinks, cold plates, airflow.
• You're self-directed: you've shipped, started or rescued a project nobody told you how to do.

Bonus

• Thermodynamic system experience
• Sealed or IP-rated enclosures
• Battery pack packaging
• Aerogel or foam insulation
• Small-batch DFM
• Consumer hardware, outdoor gear or drone experience
• Startup experience

Terms

• Fixed-term W-2 employee, 32 hours/week for 7 months, $7,000/month, plus 1% equity (terms finalized in the offer).
• This position is contingent on Thalraen receiving an NSF SBIR Phase I award. We expect work to begin around May 2027 if awarded. An award is not guaranteed.
• You must be authorized to work in the US; we can't sponsor visas.
• Finalists will be asked for a short letter of commitment to support our NSF proposal.

How to apply

Apply through Wellfound with your CV or LinkedIn, a link or photo of something you designed and built, and 3 to 5 sentences on the most interesting thing you've figured out that nobody asked you to.