Compact Wearable Electronics System Design

Design a early proof-of-concept compact wearable electronics system suitable for PCB manufacturing and assembly.

I am developing an early-stage wearable prototype that detects and communicates nervous system activation and am looking for an experienced electronics engineer to design a compact wrist-wearable PCB prototype.

This is a proof-of-concept prototype, not a regulated medical device.
The device will:
• collect physiological sensor data
• detect stress-related changes
• provide simple feedback to the wearer
The prototype is currently based on an ESP32 platform, though alternative low-power microcontrollers may be suggested if appropriate.
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Scope
Design and prototype a compact wearable electronics system suitable for integration into a stretch wristband (initially).

Goals:
• stable low-power wearable electronics
• compact PCB layout
• stress sensor integration
• Bluetooth capability
• manufacturable through JLCPCB or similar services
Flexible PCB is NOT required at this stage.
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Core Components
• Microcontroller with Bluetooth capability - ESP32 (or suggested alternative)
• Optical heart rate sensor (PPG) (MAX30102 or similar)
• Motion sensor: Accelerometer / IMU
• Vibration output
• LED output indicator
• Audio/buzzer output
• Rechargeable LiPo battery system
• Bluetooth communication
• USB charging preferred (USB-C if practical).
• Power management circuitry
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Deliverables
Required deliverables:
• Circuit schematics
• Editable PCB design files
• Gerber files
• BOM with part numbers
• Centroid / pick-and-place files
Basic hardware validation firmware preferred but not required.
All intellectual property, including designs, code, schematics, documentation & source files produced under this contract shall transfer fully to the client.
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Experience Preferred
• ESP32 or low-power embedded systems
• Wearable electronics
• Sensor integration
• PCB design for manufacturing
• Bluetooth devices
• Battery-powered systems
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Please Include
• Relevant past projects
• Estimated timeline
• Cost estimate
• Suggested technical approach

Please also briefly explain:
• how you would minimise motion artefacts and improve sensor reliability in a wrist wearable

Please begin your proposal with the word “wristband” so I know you have read the description.