used in a phase change printer a fluid transport conduit for transporting melted ink is formed from the heat generating substance described above the conduit may be circular in cross section and cut to an appropriate length for coupling an ink reservoir to a print head an electrode is provided at each end of the conduit to provide electrical energy through the conduit so that the conduit generates heat uniformly along its length the composition used to form the conduit is sufficiently flexible that it may be moved during installation without damaging the thermal generating and regulating properties of the conduit in one embodiment the conduit is formed from a composition of ntc and ptc materials having an operational range of about 60 u00b0 c to about 120 u00b0 c in another embodiment of a fluid transport apparatus used in a phase change printer the fluid transport conduit and the compressor conduit are co extruded so the fluid transport conduit is located within the compressor conduit for rigid heat generating conduits and or pumps the ntc and ptc materials may be added to a structural plastic material and the resulting mixture is melted and then extruded or injection molded into the desired final form for a conduit or a pump after cooling the structural plastic material maintains the desired shape while the ntc and ptc compounds provide the heating and the temperature regulating functions for flexible conduits the ntc and ptc compounds are added to an.