PERMANENT INCREASE OF THE ELECTRICAL-CONDUCTIVITY OF POLYMERS INDUCED BY ULTRAVIOLET-LASER RADIATION

When polyimide (Kapton) or polybenzimidazole (PBI) are irradiated by a 248 nm KrF laser, their electrical conductivity is increased permanently. Conductivity increases of up to fifteen orders of magnitude were observed, and conductivities on the order of 1-10 OMEGA-1 cm-1 were obtained. The laser-induced conductivity increase of polyimide depends on the fluence per laser shot and the total fluence delivered (dosage) and exhibits a fluence threshold of approximately 20 mJ cm-2 per laser shot, as well as a dosage threshold.