Handheld Device Hardware Prototype

I am developing a compact handheld consumer device prototype that requires integration of a rechargeable battery and small electronic module inside a custom 3D printed enclosure.

I am looking for an experienced embedded hardware / electronics engineer who can help design and prototype a small, safe, battery-powered system suitable for a handheld form factor.

The device will require:
• Integration of a rechargeable lithium battery (3.7V or similar)
• Safe charging system (USB-C or similar)
• Small heating or vapor-generating element OR similar compact load component
• Efficient power management and protection circuitry
• Compact PCB design suitable for fitting inside a slim enclosure
• Guidance on component selection and prototype assembly

The enclosure will be provided as a 3D printed housing with defined internal space constraints.

Requirements:
• Experience designing battery-powered handheld electronics
• Experience with lithium battery safety and charging circuits
• Experience with compact PCB layout
• Experience creating working hardware prototypes
• Ability to recommend components and build a functional prototype

Important:

Due to the proprietary nature of this project, shortlisted candidates will be required to sign a Non-Disclosure Agreement (NDA) before full design details are shared.

Please include examples of similar handheld or battery-powered device projects you have worked on.

This project will start with prototype development, with potential for ongoing collaboration.