In this simple procedure, water is mixed with the carbon nano tubes and dripped into a white ceramic material which is highly porous. Like a sponge, it sucks up the black liquid. If the ceramic scaffolding is chemically etched out, only the fine felted coat remains. The felt made of tiny tubes has thereby interconnected to form a network of larger tubes. The hollow spaces can be filled with polymers, to create a conductive and tear-resistant composite material.