Interfacial Adhesive Adaptation Strategies for Flexible Multilayer Pressure Sensors in Sleep Monitoring

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Flexible devices, particularly those using polydimethylsiloxane (PDMS) substrates, often suffer from poor interfacial adhesion and mechanical mismatches in multilayer structures.
• These limitations hinder the development of stable and repeatable flexible pressure sensors crucial for advanced applications.

Purpose of the Study:

• To synthesize a novel PDMS material with internal dynamic cross-linking capabilities to address interfacial stability and mechanical compatibility issues in flexible sensors.
• To develop a multilayer flexible pressure sensor with enhanced sensitivity, sensing range, and long-term reliability.
• To demonstrate the sensor's application in medical health monitoring, specifically for classifying sleep apnea-hypopnea syndrome using machine learning.

Main Methods:

• Synthesis of PDMS with dynamic cross-linking ability, exhibiting self-healing properties at room temperature.
• Fabrication of a multilayer flexible pressure sensor using a composite ink with PDMS as an additive, ensuring material homogeneity.
• Creation of microconvex structures on the multilayer sensing layer via a microstructural template to enhance sensor performance.
• Development of a neural network model for machine learning-based classification of sleep conditions.

Main Results:

• The synthesized PDMS demonstrates excellent tensile properties, flexibility, and room-temperature self-healing capabilities.
• The fabricated sensor exhibits strong peeling resistance and interfacial adhesion due to material homogeneity.
• The multilayer structure with microconvex features significantly improves the sensitivity and sensing range of the pressure sensor.
• The neural network successfully classifies various sleep conditions, including normal sleep, tachycardia, sleep apnea, sleep talking, snoring, and rapid eye movement.

Conclusions:

• The dynamic cross-linking PDMS material effectively resolves interfacial adhesion and mechanical mismatch challenges in flexible multilayer devices.
• The developed multilayer flexible pressure sensor offers improved stability, sensitivity, and reliability for practical applications.
• The sensor shows significant potential for non-invasive medical health monitoring, particularly in diagnosing sleep-related respiratory disorders through advanced machine learning algorithms.