An approach (a combination of techniques) to studying poly(ethylene terephthalate) (PET) fibers metal-coated by the sputtering of copper is reported. The effects of copper coatings on the surface morphology, surface chemistry, and surface energy were investigated with atomic force microscopy (AFM), energy-dispersive Xray (EDX) analysis, and dynamic contact angle measurements. Functional nanostructures formed by sputter coating on the fiber surface were revealed with AFM. The introduction of copper onto the fiber surface was also detected by EDX analysis. The fibers functionalized by the sputter coating resulted in changes in the surface energy measured with the advancing and receding contact angles. Both the advancing and receding contact angles were reduced after sputter coating by copper, but the contact angle hysteresis was significantly increased as the coating was applied. The surface resistivity measurements revealed that sputter coating by copper considerably improved the surface conductivity of the PET fibers. (c) 2008 Wiley Periodicals, Inc.