Ivan Minev1
University of Sheffield1
Electrode arrays are a crucial component of many types of bioelectronic interface. They have found applications in implantable devices such as deep brain stimulators and cochlear implants and in non-invasive systems for ElectroMyoGraphy (EMG) and ElectroEncephaloGraphy (EEG) measurements. Despite being a relatively mature technology, electrode arrays have not reached their full potential in the clinic and in research. For example, producing electrode arrays that are sufficiently compliant to match the mechanical properties of soft tissues and tailored to individual patients remains challenging. Rapid prototyping approaches are uniquely placed to address this because they can handle soft materials and offer fast design iteration.<br/>I will discuss our efforts to adapt multi-material 3D printing for fabrication of implantable microelectrodes and wearable sensors. A range of electrically conductive composite materials and their printing via direct ink writing will be presented. The composites are formulated from electrically conductive particles (platinum, graphite, iridium) and silicones. The resultant electrode arrays are flexible and stretchable and maintain their electrical functionality at strains of at least 20%. As implants, I will present their application on the surface of the brain and spinal cord, around peripheral nerves an inside muscles in animal models. As wearable arrays, printed arrays were applied for sensing human hand EMG, pinch pressure and thumb position.<br/>Printed electrode and sensor arrays are an accessible technology for pre-clinical work in various animal models of disease or trauma and may in future open up possibilities for patient tailored bioelectronic skins or implants.