Microstructures and electrical conductance of silver nanocrystalline thin films on flexible polymer substrates

Using sputtering technique, silver nanocrystalline thin films were deposited on two different polymer substrates, namely pretreated nylon and polyester fabrics, under identical conditions. It is found that the difference of the electrical conductance between the two samples is quite large. The highest conductivity obtained from the coated nylon fabric is 2.4 x 10(7)Sm(-1), indicating the feasibility to fabricate wearable electrodes using silver coated fabrics. However, the electrical conductance of the coated polyester fibre is found to be lower by six orders of magnitude. Transmission electron microscopy reveals that the silver grains coated on the polyester fibre are spatially separated while the silver grains coated on the nylon fibre are connective. The pre-deposition surface conditions of the fibres are suggested to be responsible to the remarkable differences in the electrical conductance and microstructures of the silver nanocrystalline films. (c) 2009 Elsevier B.V. All rights reserved.