Photocurable 3D-printed AgNPs/Graphene/Polymer nanocomposites with high flexibility and stretchability for ECG and EMG smart clothing

A flexible and stretchable photocurable resin was prepared by varying the oligomer/acrylate monomer ratio. The electrical conductivity of the resin was enhanced by adding graphene and silver nanoparticles (AgNPs). Different electrode surface structures and line structures were customized using photocurable 3D printers to detect physiological signals such as electrocardiograms (ECG) and electromyograms (EMG). An amphiphile dispersant, PIB-POE-PIB, was utilized to reduce graphene aggregation. Non-covalent bonding between graphene and the lipophilic chain of PIB, as well as the hydrophilic chain of POE, increased the stability of graphene in aqueous solutions. By combining the reduced AgNPs with the elastic photocurable resin via photopolymerization under UV exposure, AgNPs/graphene/polymer nanocomposite sensing electrodes with high flexibility were prepared. The cured resin had a low surface resistivity (approximately 1 × 102 Ω/sq), with a strain of up to 300 % at fracture. After washing and perspiration tests, the resistivity was maintained at 6 × 102 Ω/sq. Finally, electrodes with different surface structures and line structures were printed using photocurable 3D printers to measure the ECG and EMG of the human body during various exercises, demonstrating that the advantages of photocurable 3D printing can be successfully integrated with wearable electronic devices to produce smart textiles for bioelectric signal detection.