Biodegradable Strain Sensor-Based Wearable Mask for Continuous Real-Time Monitoring of Respiration

Traditional respiration sensors, such as piezoelectric, capacitive, and resistive sensors, face challenges in continuous real-time monitoring due to sensor rigidity, discomfort during prolonged wear, and limited adaptability to diverse body shapes. In addition, the use of nonbiodegradable materials contributes to electronic waste. This study introduces a multilayer graphene (MLG) and Arabic gum-based biodegradable strain (GBS) sensor for real-time noninvasive respiration monitoring. The MLG was electrochemically exfoliated from a graphite rod, ensuring high flexibility and sensitivity. The sensor exhibited excellent sensitivity (3.75%/%RH) and durability of 5600 bending cycles. Furthermore, GBS sensors demonstrated complete degradation in water within five days, addressing environmental concerns. The developed wearable mask integrated with the GBS sensor and a wireless electronics module successfully monitored various respiration patterns, including normal breathing, post-exercise respiration, fast respiration, exhalation time variations, and different exhalation periods (long, normal, and short). In addition, the sensor could track physical activities such as hand folding, wrist bending, ankle, and neck movement, demonstrating its versatility beyond respiration monitoring.