How to achieve high electrical conductivity in aligned carbon nanotube polymer composites

Carbon nanotube reinforced polymer composites may provide a unique option for the aviation industry due to their high strength-to-weight ratio and multifunctionality. Specifically their electrical conductivity and consequent shielding capabilities can be strongly enhanced by featuring vertically aligned nanotube arrays in the polymer composites. We report here a detailed study of the electrical transport mechanisms within aligned carbon nanotube reinforced polymer composites. The experimental part of our investigation relies on extensive use of both macroscopic and high spatial resolution experimental techniques by which we shed light on the factors dominating the electrical transport, namely the contact resistance which depends on the wetting properties of CNT-metal interface, and the resistance at point-junctions which scale with the size of interconnecting tubes. Our modeling effort well describes our experimental observations and reveals the key parameters to achieve high nanocomposite intrinsic electrical conductivity and to reduce its interfacial contact resistance.