Sustainable electrodes for biosignal sensing based on cellulose and marine sponges

Abstract

The need for advanced biosignal sensors in health monitoring and human–machine interfaces has highlighted the limitations of current wet and dry electrode solutions, which lack environmental sustainability, breathability, long-term usability, multi-functionality, and adaptability to body movements and complex surfaces. This research addresses these issues by investigating biodegradable bioelectrode scaffolds from natural materials wood, marine sponges and cellulose sponges infused with carbon nanotubes (CNTs) and hydrogels to yield electrical conductivity and optimize performance. We evaluated the electrical properties of these hybrid sponge electrodes under cyclic and static compression, performed a frequency-dependent impedance analysis, and conducted ageing tests to assess long-term stability. We have shown that hybrid sponges are an excellent product when impregnated with CNTs and are suitable for long-term measurements; when additionally impregnated with liquid hydrogel, they become an exceptionally conductive product for demanding applications. Our findings indicate that cellulose and marine sponge-based bioelectrodes could maintain high performance and sustainability, with in vivo ECG tests confirming their potential for medical applications.

Graphical abstract