CMOS-Compatible ZrO₂-Based Film for Photoplethysmography Sensors Enabling Accurate and Sensitive Health Monitoring

Area of Science:

• Biomedical Engineering
• Materials Science
• Cardiovascular Technology

Background:

• Photoplethysmography (PPG) is a noninvasive method for monitoring cardiovascular parameters like heart rate and blood oxygen saturation (SpO2).
• Existing PPG devices suffer from rigidity, bulkiness, high cost, power consumption, and motion artifact susceptibility.
• There is a need for improved PPG sensors for reliable and accessible health monitoring.

Purpose of the Study:

• To develop a novel, self-powered, miniaturized, and low-cost PPG sensor.
• To overcome the limitations of current commercial PPG technology.
• To enhance the stability and accuracy of PPG measurements.

Main Methods:

• Utilized a CMOS-compatible fluorite-type ferro/pyroelectric HfₓZr₁₋ₓO₂ thin-film photodetector.
• Developed a self-powered, miniaturized photodetector device.
• Evaluated sensor performance against conventional PPG devices.

Main Results:

• The novel photodetector demonstrated 26% higher responsivity and 23% improved sensitivity.
• Achieved high accuracy (<2% error) in SpO2 estimation.
• Showcased superior performance in sensing blood volume changes in microvascular tissues.

Conclusions:

• The developed self-powered PPG sensor overcomes key limitations of existing technologies.
• The sensor offers enhanced performance for cardiovascular parameter monitoring.
• This technology holds significant potential for widespread adoption in health monitoring applications.