Carbon Nanotube (CNT) Elastomers for Sensing Applications: A Narrative Review

Elastomers are traditionally considered materials with low tensile strength and minimal electrical conductivity. Carbon nanotubes (CNT) are classified as fullerenes, or carbon-based materials forming a molecular mesh, that assume a cylindrical shape and display remarkable properties, such as high tensile strength and enhanced electrical conductivity as compared to other carbon allotropes. Elastomers doped with carbon nanotubes form CNT elastomers, which act as semi-conductors and can be formulated to exhibit many useful characteristics for the design of various sensors, such as strain gages. While CNT elastomers have been studied for more than 20 years, there are relatively few, if any, commercial sensor products utilizing this innovative technology. In this chapter, we survey selected portions of the CNT literature, explore the operation and characteristics of CNT elastomers, and consider some CNT elastomer requirements of potential interest for the design of sensors.