Carbon Nanotube-Based Hydrogel Composites for Intra-Ear EEG Electrodes

Paper i proceeding, 2026

In-ear electroencephalography (in-ear EEG) – an emerging field in neurotechnology – has significant potential for continuous and discreet monitoring of brain electrical activity. The concept of in-ear electroencephalography can only be realised through the integration and use of biomaterials in the final design of the devices. The performance of recording systems depends considerably on the materials used in the manufacture of electrodes, which must integrate properties such as biocompatibility, comfort for users and mechanical stability. In this study, the biocompatibility and mechanical properties of composite hydrogels based on methacrylated gelatin (GelMA 10%), 2-hydroxyethyl methacrylate (HEMA) and carbon nanotubes (CNT) was assessed in order to evaluate their potential for biomedical applications, particularly in the field of implantable or wearable devices, such as intra-aural EEG electrodes. To this end, the research aimed to synthesize and characterize these polymeric hydrogels, varying the CNT ratios, evaluate their cytocompatibility through MTT tests and cell morphology analyses (Calcein-AM and DAPI) on human dermal fibroblasts. Simultaneously, relevant mechanical properties, such as elastic modulus and compressive strength were determined to verify the scaffolds suitability for applications involving a direct contact with human tissue. By correlating biological and mechanical data, the study aimed to identify an optimal composition that ensures both biological compatibility and adequate structural performance for effective integration into in-ear EEG monitoring systems.