Carbon nanomaterials electrically conductive

In the nanotechnology field, carbon-based materials and associated composites have received special attention both for fundamental and applicative research. In the first kind, carbon compounds may be included, often taking the form of a hollow spheres, ellipsoids, or mbes. Spherical and ellipsoidal carbon nanomaterials are referred to as fullerenes, while cylindrical ones are called nanombes and nanofibers. In the second class, one includes composite materials that combine carbon nanoparticles with other nanoparticles, or nanoparticles with large bulk-type materials. The unique properties of these various types of nanomaterials provide novel electrical, catalytic, magnetic, mechanical, thermal, and other features that are desirable for applications in commercial, medical, military, and enviromnental sectors. This is the case for conducting polymers (CPs) and carbon nanombes (CNTs) [1-5]. 

Besides the intrinsic conductive polymers, some deformable polymers, such as shape-memory polymers, are usually activated by heating. After incorporating with conductive fillers, such as carbon nanomaterials, they can be simulated by the electricity through Joule heating (Liu et al., 2009 Hu and Chen, 2010 Koerner et al., 2004). This kind of electro thermally active polymer composites can produce expansion/contraction and bending behaviors upon with the electricity. Moreover, these actuators can work durably... 

However, the electrical conductivity of the carbon nanomaterials is vulnerable to degradation due to the inefficient dispersion in a large-scale actuator. To this end, some metallic additives have been incorporated into the carbon-based electrode to enhance the electrical conductivity and actuation stability For instance, for the IPMC actuator where the reduced graphene oxide was used as electrode, the electrical conductivity of the electrodes could be efficiently improved after introduction of Ag nanoparticles (Fig. 8.2E) (Lu et al., 2013). As a result, both the actuation frequency and stability could be improved. Upon application of a low voltage of 1V, the actuator could be driven at a wide frequency range (0.01-10 Hz), and no obvious decrease in displacement was observed over 500 cycles of actuation. 

In biomedical research, carbon nanomaterials (CNMs) are considered to be the most attractive materials since they possess distinctive physical and chemical properties such as excellent mechanical strength, electrical and thermal conductivity, and optical properties... 

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