Recent Progress on Poly(3,4-Ethylenedioxythiophene):Poly(Styrenesulfonate) Bioelectrodes

Sensing bioelectrical signals is of great significance to understand human disease. Reliable bioelectronic interface is the guarantee of high-quality bioelectrical signals. The unique electrochemical property and the mixed ionic and electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) make it an ideal material for the skin/tissue-electronic interface. However, pristine PEDOT:PSS-based devices cannot meet the requirements for practical use. Toward this end, herein, the development of PEDOT:PSS-based electrodes and their most recent advances in sensing bioelectrical signals are summarized. First, the generation mechanism of bioelectrical signals is introduced in detail. Then, according to the characteristics of bioelectrical signals, the requirements of bioelectrodes are discussed. Next, representative achievements for improving conductivity, stretchability, and stability of PEDOT:PSS are introduced. Bioelectrical signals such as electromyogram (EMG), electrocardiogram (ECG), electrooculogram (EOG), and electroencephalogram (EEG) are successfully recorded by these PEDOT:PSS-based electrodes. Finally, a brief summary is provided, and the opportunities and challenges are also discussed.