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 Ω−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 ∼20 mJ cm−2 per laser shot, as well as a dosage threshold.