Highly-sensitive carbon nanotube based sensors using everyday fabrics for human motion analysis

Abstract

Analyzing human motion is becoming increasingly important for patients requiring rehabilitation and athletes to improve performance. Motion capture cameras, currently used for human motion analysis are prohibitively expensive and complicated to use. There exists a critical need for developing innovative and cost-effective techniques to analyze motion outside of the laboratory. In this work, low-cost and comfortable wearable sensors can be created by coating everyday fabrics with nanocomposite coatings based on carbon nanotubes. A dip-coating process is used to coat fibers in a knitted fabric to create an elongation sensor. The nanocomposite coating makes the fabric electrically conductive and imparts piezoresistive sensing functionality where electrical resistance changes proportionally to mechanical deformation. A variety of mechanical tests are performed the electrical/mechanical coupling behavior. Preliminary results show ultra-high sensitivity with a resistance change of over 3,000% when an elbow sleeve sensor is worn while flexing. The sensors offer the possibility to be non-invasively integrated into clothing to create ‘smart garments'.