Biosensor Integration in Smart Textiles

Abstract

Wearable health monitoring requires biosensors that are comfortable, unobtrusive, and capable of continuous operation during daily activities -- requirements poorly met by rigid electronics attached to the skin with adhesives. Smart textiles integrate biosensors directly into fabrics worn as everyday garments, enabling seamless physiological monitoring without user awareness or compliance burden. However, textile-integrated biosensors face unique challenges: mechanical deformation during body movement, sweat exposure and laundering degradation, signal artefacts from textile-skin contact variability, and power supply for continuous operation. This study developed and evaluated five textile biosensor platforms -- conductive yarn ECG electrodes, screen-printed strain sensors for respiration, embroidered piezoresistive pressure arrays, fibre-optic photoplethysmography (PPG) sensors, and a proposed multi-modal smart shirt (MMSS) integrating all four modalities with a flexible microcontroller and Bluetooth Low Energy (BLE) transmission -- for continuous cardiorespiratory monitoring in 24 healthy volunteers during 72-hour free-living wear. MMSS achieved clinical-grade ECG quality (correlation r = 0.96 with Holter monitor; QRS detection sensitivity 98.2%), respiratory rate accuracy (RMSE 1.4 +- 0.4 breaths/min vs reference pneumography), heart rate from textile PPG (RMSE 2.8 +- 0.8 bpm vs pulse oximetry), and posture classification (94.6% accuracy, 7 postures). Signal quality was maintained after 50 wash cycles (ECG r degradation <3.2%), and the garment was rated 8.4/10 for comfort by participants. These results establish multi-modal smart textiles as a viable platform for continuous ambulatory health monitoring and provide a comprehensive benchmark for textile biosensor performance under real-world conditions.