3D Expandable Microwire Electrode Arrays Made of Programmable Shape Memory Materials

Nitinol, a biocompatible material with shape memory effect and superelasticity, has been used in various biomedical applications. Here we demonstrate a 3D expandable nitinol microwire electrode array that can be programmed to the desired shape to conform to the brain vasculature, minimizing the vessel damage during implantation. We developed a fabrication process for precisely setting the shape of nitinol microwires and assembling them to form electrode arrays. We tested our nitinol microwire array in in vivo animal experiments and successfully demonstrated that our array can detect single spikes as well as local field potentials with minimum tissue and vessel damage.