Microvaristors are tiny electroceramic particles, which have highly nonlinear, voltage controlled electrical transport properties and can be used as active fillers in a variety of insulating matrix materials for functional composites. Due to the internal grain boundary structure, each individual microvaristor particle shows an IV-characteristics similar to the one known from bulk ceramics, except for the scaled down switching voltage. By controlling the material formulation, the particle morphology and the sintering conditions the switching characteristics of microvaristors can be tailored for specific applications.
Greuter, F., Siegrist, M., Kluge-Weiss, P., Kessler, R., Donzel, L., Loitzl, R., & Gramespacher, H. J. (2004). Microvaristors: Functional fillers for novel electroceramic composites. In Journal of Electroceramics (Vol. 13, pp. 739–744). https://doi.org/10.1007/s10832-004-5185-9