Preparation and applications of flexible conductive organohydrogels with ultrahigh gas permeability

Abstract

The accurate and real-time monitoring of human physiological signals such as electromyography (EMG) and electrocardiogram (ECG) is of great significance. New composite flexible conductive organohydrogels, GCPP-Au, composed of gelatin (Gel), carboxylated carbon nanotubes (C-MWCNTs), polypyrrole (PPy), and gold nanoparticles (AuNPs) were fabricated. The GCPP-Au composite flexible conductive organohydrogels possessed excellent mechanical properties, electrochemical properties, and ultrahigh permeability. Its elongation at break was 253%, fracture strength was 1.52 MPa, conductivity was 2.33 S m⁻¹, and sensitivity was high. Due to the regulation of PVP, GCPP-Au presented uniform pore distribution and high permeability. The average pore size was 103.8 μm, water vapor transmission (WVT) and water vapor permeability (WVP) were 126.21 g h⁻¹ m⁻² and 244.44 × 10⁻⁷ g m⁻¹ Pa⁻¹ h⁻¹, respectively, which significantly improved the wear comfort. GCPP-Au presented high strain transfer sensitivity and can be used as a wearable device for motion monitoring. At the same time, it could be applied to the sensing site of the array pressure sensor to simulate the ‘electronic skin’. The GCPP-Au electrode accurately monitored human physiological signals (EMG and ECG) in real-time and realized gesture recognition. Human–computer interaction was carried out including making arm and wrist-integrated sensors to control the Russian square movement. The highly breathable GCPP-Au electrode prepared in this work has broad application prospects in flexible wearable electronic devices.