Carbon nanotube fibers: smart, strong and sensitive

It is today well established that carbon nanotubes exhibit remarkable chemical and physical properties. Significant progresses have been achieved at the level of their synthesis, and major industrial chemistry companies are planning their mass production in a near future. Nevertheless, the exploitation of nanotube properties remains a challenge for appealing technologies and applications. Among them, one can cite high-performances materials, micro-sensors for biological applications or electromechanical actuators for robotic and medical technologies. As synthesized nanotubes are under the form of a light and disordered soot. Depending on the targeted applications, carbon nanotubes have to be dispersed in a matrix, assembled or macroscopically oriented in order to efficiently exploit a given property. We describe here studies we conduct in this field at the Centre de Recherche Paul Pascal. We mainly use classical concepts of physical-chemistry of complex fluids to optimize dispersions and assemblies of carbon nanotubes. A particular emphasis is given to a simple wet-spinning process we have developed to produce continuous fibers of oriented nanotubes. We discuss the mechanical, electrochemical and electromechanical properties of the obtained fibers. We draw the conclusion that carbon nanotube fibers are particularly promising materials to efficiently exploit the properties of carbon nanotubes.