Israeli research points way to improved performance for composite-based electronics
A research from the Hebrew University in Jerusalem led by Isaac Balberg has shown how electrical resistivity varies with the concentration of the particles in composite materials. The discovery could have an impact on the performance capabilities of flexible electronics-based products.
To understand the dependence of resistivity on the concentration of the electrically conducting particles, the researchers applied percolation theory. The theory provides a map for the number and size of clusters of adjacent particles as the concentration of particles increases. In the study, the researchers noted that the resistances involved in the electrical conduction can have a given discrete series of values unlike a single one or a continuous distribution found in many previous works.
Balberg and colleagues made the theoretical prediction – and proved experimentally using granular metal and carbon-black composites – that the dependence of the electrical resistance on the conducting particle concentration is manifested by a staircase. This was particularly obvious in nanometric scale systems, in which there is a well-defined discrete series of distances between a particle and its neighbours. Each stair exhibits a universal behavior – independent of the details of the system – predicted by percolation theory. The electrical resistivity associated with subsequent stairs decreases as the concentration of the conducting particles increases.
The work also shed light on many previously unexplained data related to characteristics of various types of composites, such as those containing carbon nanotubes or graphene.
Reference: Balberg et al. (2013), The percolation staircase model and its manifestation in composite materials, European Physical Journal B, DOI 10.1140/epjb/e2013-40200-7
If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :
