Fig. 1: Schematic illustration for the preparation of PEDOT:PSS/WPU/D-sorbitol films.

a Chemical structures of PEDOT:PSS, WPU, and D-sorbitol. b Fabrication of the PWS blend films: Firstly, mixing of PEDOT:PSS, WPU and D-sorbitol; Secondly, drop-casting the blend solution in a mold; Thirdly, drying at 60 °C. The resulting blend film can be used as an adhesive electrode on the skin for epidermal biopotential detections such as electrocardiography (ECG), electromyography (EMG), and electroencephalography (EEG).