Hybrid Nanocomposite Membrane for Wearable Bioelectronics

There are strong needs for flexible and stretchable devices for the seamless integration with soft and curvilinear human skin or irregular textured cloths. However, the mechanical mismatch between the conventional rigid electronics and the soft human body results in many issues including contact breakage, or skin irritation. Due to the mechanical and electrical versatility of nanoscale forms, various nanomaterials have rapidly established themselves as promising electronic materials, replacing rigid wafer-based electronics in next-generation wearable devices. Here, we introduce a flexible, wearable bioelectronic system using an elastomeric hybrid nanocomposite, composed of zero-dimensional Carbon Black (CB) and one-dimensional Carbon Nanotubes (CNTs) and silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix. Those materials were chosen due to their good electrical properties and their different length scale providing a continuous connection in the flexible PDMS matrix. To achieve a homogeneous dispersion, these nanomaterials were mechanically mixed in PDMS under shear flow using an overhead mixer. A hybrid nanocomposite membrane with dimensions of 15 mm diameter was then prepared by replica molding process. The electrical properties of the nanocomposite were measured over 5, 10 and 15hrs mixing time to investigate the point of electrical stability of the electrode and the electrical performance during EMG signal measurement. This soft nanocomposite, laminated on the skin, enables highly sensitive recording of electromyograms.