  We show that the formation of a gel by conducting colloidal particles leads
to a dramatic enhancement in bulk conductivity, due to inter-particle electron
tunneling, combining predictions from molecular dynamics simulations with
structural measurements in an experimental colloid system. Our results show how
colloidal gelation can be used as a general route to huge enhancements of
conductivity, and suggest a feasible way for developing cheap materials with
novel properties and low metal content.
