Simulation of electrical conductivity for nanoparticles and nanotubes composite sensor according to geometrical properties of nanomaterials
The nanocomposite based on conductive nanoparticles and nanotubes are widely used for stretchable strain sensors application. Since electrical properties varies by the geometrical properties of nanomaterials, it is important to understand the effects of nanomaterials by strain to optimise the sensor performance. However, it is difficult to fabricate strain sensor using nanomaterials with exactly desired properties. Hence, in this study, we have developed a simulation method for conductive nanoparticles and nanotubes composite using Lennard-Jones potential model and the voter model. First, we optimised the distribution of nanocomposites using Lennard-Jones potential model in the boundary conditions according to external strain. Then, we counted the average attachment among nanomaterials by strain using the voter model which is directly influence electrical conductivity of strain sensors. Moreover, we validated proposed simulation method using experimental value of fabricated strain sensor with various nanocomposite composition ratio and packing ratio. Using the suggested method, the effect of geometrical properties of nanomaterials can be accurately estimated with low simulation cost. Finally, we obtained the simulation value for strain sensor performance by various diameter of nanoparticle, diameter of nanotube, and length of nanotube. We demonstrated that the diameter of nanoparticle is a primary factor for sensor performance while the diameter of nanotubes does not have great influence. Based on the simulation results, it was confirmed that the change of electrical conductivity according to the strain is the largest at small and uniform nanomaterials. The developed simulation method can be applied to the general analysis of electrical properties for nanocomposites.