Continuous Glucose Monitoring Sensor PCB

This project involves the design and manufacturing of a miniature flexible printed circuit board assembly (PCB) for a continuous glucose monitoring (CGM) system. This PCB acts as the wearable sensor's electronic backbone, responsible for electrochemical sensing, signal conditioning, and wireless data transmission for diabetes management.

Key PCB Specifications:
Base Material: Polyimide (PI) flexible substrate with 25μm thickness, enabling comfortable skin adhesion and bendability
Layer Stackup: 2-layer FPC with dynamic flex capability, supporting >10,000 flex cycles without circuit failure
Copper Weight: 0.5 Oz rolled annealed copper for enhanced flex life and consistent impedance
Board Dimensions: 15mm × 8mm, ultra-compact form factor for discreet wearable application
Surface Finish: Immersion gold over nickel for electrode biocompatibility and stable electrochemical performance
Assembly Process: Chip-on-flex (COF) assembly with anisotropic conductive film (ACF) bonding for bare-die ICs
Environmental Protection: Medical-grade parylene coating providing biocompatible barrier against body fluids
Functional Role:
This miniature PCB is the technological heart of the CGM system:
Electrochemical Sensing: Potentiostat circuit maintains precise voltage bias across enzyme-coated electrodes for accurate glucose measurement
Signal Conditioning: Transimpedance amplifier converts picoamp-level sensor currents to measurable voltage signals
Data Processing: Ultra-low-power microcontroller runs calibration algorithms and stores historical readings
Wireless Communication: Bluetooth Low Energy (BLE) 5.0 module transmits glucose data to smartphone app every 5 minutes
Power Efficiency: Nanowatt-level sleep mode extends battery life to 14 days on a single coin cell