Electrical Resistance of Carbon Nanotube Yarns Under Compressive Transverse Pressure

This letter reports on the impact of compressive pressure on the electrical properties of carbon nanotube (CNT) yarns fabricated by dry Web-spinning and heat-treatment processes. Under increasing applied compressive pressure in the radial direction of the yarn, the electrical resistance of CNT yarns gradually decreased by 2.8% at a threshold applied pressure of 60 kPa where the resistance change is saturated. The decrease of CNT resistance with increasing pressure is attributed to the increase in the volume fraction of CNT, resulting in the increase of the effective junctions between adjacent CNTs, and the reduction of the tunneling distance between single CNTs. CNT yarns embedded in elastomers show high potential as an advanced functional element for a wide range of mechanical sensing applications including flexible pressure and tactile sensing.