Shear induced CNT/PDMS conducting thin film for electrode cardiogram (ECG) electrode

A CNT-based electrode was developed for flexible electrocardiogram (ECG) electrodes with a mixture of polydimethylsiloxane (PDMS) and carbon nanotubes (CNT). In this study, the electrical characteristics of the electrode were evaluated as to the CNT concentration, CNT dispersion and fabrication condition. To obtain good electrical performance of film, the good dispersion of CNT and PDMS is one of great challenges, and we employed the modified two-step method for this purpose. The electrical property of the film by the two step method was much more enhanced than that by the conventional one step method. The electrical properties of the film depended on the film thickness which was controllable by spin coating speed and the flow property of the fluid. Based on these experiments, we found that ECG electrodes require less than 1. 5wt% CNT for the desired performance. The 1. 5wt% CNT/PDMS film showed optimal mechanical and electrical performance which enabled it to be used as an ECG electrode. We measured the ECG signals from the human skin, and the signal quality was comparable to commercial ECG electrodes.