Soft, Conductive, and Anti‐Freezing Conducting Polymer Organohydrogels

Abstract

Abstract Soft and conductive materials are highly desirable for wearable electronics. In particular, anti‐freezing, long‐water retention, and highly conductive gels with Young's modulus matching that of biological tissues, show promise in bioelectronics. Herein, soft organohydrogels obtained by mixing poly (3,4‐ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS), ethylene glycol (EG), and tannic acid (TA) are reported. The PEDOT/EG/TA organohydrogels exhibit a low compressive Young's modulus of ≈20 kPa, a conductivity of ≈6 S cm−1, as well as anti‐freezing and water retention properties. Epidermal patch electrodes prepared using the PEDOT/EG/TA gel exhibit low skin–electrode impedance at low frequency (1–100 Hz) and high‐quality electrocardiography (ECG) and electromyography signal recordings. Moreover, these gels demonstrate long‐term stability with high ECG recording quality after being placed under ambient conditions for seven days.

Keywords

• anti‐freezing
• high conductivity
• long‐water retention
• organohydrogels
• PEDOT:PSS