Heat-Cool Thermos Prototype Design

I need a compact 500 ml thermos that can both chill and warm drinks on demand. The bottle will travel with me—morning commutes, gym sessions, office hours, and the occasional winter hike—so durability and portability are non-negotiable.

Core requirements
• Dual active temperature control: integrate heating and cooling elements that I can switch manually rather than through presets or automation.
• Stable insulation: maintain target temperature for at least two hours after the element is switched off.
• Safe food-grade inner liner (stainless steel preferred) plus an exterior that stays comfortable to grip in cold weather.
• Rechargeable power solution with straightforward USB-C charging; a removable battery pack would be a bonus for airline compliance.
• Simple interface—ideally a single knob or slider with clear hot/cold indicators and an LED status light.
• Leakproof lid and a base that fits standard cup holders and bicycle bottle cages.

What I’d like from you
1. Detailed CAD files and exploded views ready for manufacturing discussion.
2. A parts list including recommended heating/cooling modules, insulation materials, and battery specs.
3. Thermal performance calculations that show expected temperature change rates for both hot (up to 60 °C) and cold (down to 5 °C) modes.
4. Visual mock-ups (renders or sketches) so I can assess ergonomics and aesthetics.
5. Guidance on prototyping: where to source components, estimated build cost, and any potential safety or regulatory considerations (CE, FCC).

I’m open to iterative feedback rounds and minor refinements as the concept develops. If you have prior experience with portable electronics, drinkware, or Peltier-based designs, please highlight it and include sample work or photos.