Large variation in Young's modulus of carbon nanotube yarns with different diameters

Twist-spun carbon nanotube (CNT) yarns are composed of numerous CNTs and their bundles with entangled and twisted structures. In this paper, we studied the mechanical properties of CNT yarns. The individual CNT, a component of yarn, is well known to have an extremely high mechanical strength. However, CNT yarns are very flexible and relatively free to transform their shapes, showing the potential for application in the design of wearable devices. Since CNT yarns have two opposing characteristics at the same time, a wide range of Young's modulus can be achieved by simply changing the geometrical structure while using the same fabrication process. We also suggest that CNT yarns can be utilized as the base material for several applications that require different stresses in a structure, such as bioimplants or foldable devices.