Stretchable human interface using a conductive silicone elastomer containing silver fillers

Prototype, dry and flexible electrodes for noninvasively measuring biological signals were prepared by using an electrically conductive silicone elastomer containing silver fillers. The conductive silicone elastomer exhibits a sufficiently low electrical resistivity for measurement of biological signals, as well as excellent flexibility. Although biological signals in the head, including electrical signals related to ocular movement and brain waves, were difficult to measure stably using electrodes without any surface treatments, due to polarization at the interface between an electrode and the skin when the surface area of the electrode was excessively large, the signals could be detected successfully using electrodes with appropriate dimensions. It was suggested that the polarization during the biological signal measurement could be suppressed by the deposition of carbon film on the electrodes. The carbon coating is a useful surface treatment for the bio-sensing electrodes because the chemical stability and biocompatibility of the electrodes would also be expected to be improved. The electrodes are expected to be applied to the development of novel electronic devices, controlled by biological signals.