Soft-Goods Product Engineer Needed for Wearable Ice-Cooling Prototype

I’m looking for an experienced soft-goods product engineer or technical product developer to help turn a wearable sports-cooling concept into a functional prototype and manufacturer-ready design. The product is a lightweight upper-body cooling cape intended for short-term use by athletes between rounds or periods of competition. It uses refillable, waterproof chambers that hold ordinary ice cubes and melted water. The design must provide strong cold transfer while remaining comfortable, durable, quick to install and easy to drain. The overall concept, preliminary dimensions, visual design and first-pass CAD files have already been developed. I need someone who can evaluate the design, correct the pattern and construction details, select compatible materials and help create a working prototype. Relevant experience should include: * Soft-goods or technical-apparel product development * TPU film, TPU-coated nylon or similar waterproof materials * RF/HF welding, heat welding or ultrasonic seam construction * Hydration bladders, inflatable products, dry bags or waterproof reservoirs * Wearable-product pattern development and ergonomic fit * Drain valves, waterproof fill openings and reinforced hardware attachment * Creating manufacturer-ready technical drawings, patterns and bills of materials Initial scope of work: 1. Review the concept artwork and preliminary CAD package. 2. Recommend appropriate outer, reservoir and body-facing materials. 3. Refine the dimensions, curvature and fit for an average adult athlete. 4. Engineer the chamber, internal-baffle and seam-weld layout. 5. Specify suitable fill closures, drain valves and magnetic retention hardware. 6. Update the 2D CAD patterns and technical package. 7. Produce or coordinate one functional prototype. 8. Identify design problems and recommend revisions after testing. 9. Deliver updated CAD files, patterns, bill of materials and assembly specifications. Key prototype requirements: * Holds ordinary ice cubes rather than removable gel packs * Separate front and rear waterproof reservoirs * Ice must move freely into the chambers without becoming trapped * Meltwater must drain quickly and completely * Strong cold transfer through the body-facing layer * Compact rear section covering only the shoulders and upper back * Quick placement and removal * Durable, cleanable and resistant to repeated filling and draining * Target filled weight of less than 4 pounds Please include the following with your proposal: * Examples of similar soft-goods or welded-bladder products * Your experience with RF/HF-welded TPU construction * Whether you can personally build the prototype or work with a sample facility * Your recommended development process * Estimated cost and timeline for the initial engineering and prototype phase * Any anticipated technical concerns based on this description The complete design package and detailed concept images will be shared with shortlisted candidates after a confidentiality agreement is signed. This project may lead to additional prototype revisions and manufacturing-sourcing work. Please do not apply if your experience is limited to rigid mechanical parts, architectural CAD or garment styling without waterproof-product engineering. Complete materials will be provided to shortlisted candidates after a confidentiality agreement.