Systems and methods for lightning strike materials are disclosed. The material may include a carbon fiber tow. Carbon nanotubes may be grown on carbon fibers within the carbon fiber tow. The carbon nanotubes may cause the carbon fibers to separate, decreasing a carbon tow fiber volume fraction of the tow. The growth of the carbon nanotubes may be controlled to select a tow fiber volume fraction of the tow. The lightning strike material may transmit electricity to decrease damage to the composite structure in case of a lightning strike.