Microscopic Characterization of Failure Mechanisms in Long-Term Implanted Microwire Neural Electrodes

The development of integrated circuits greatly enhances brain-computer interface technology. The degradation of the implanted neural electrodes is a key issue. The scanning electron microscope and energy dispersive spectrometer techniques are used to characterize the evolution of the microscopic morphology and element migration of implanted microwire electrodes containing 32 channels together with the recorded neural signals at different implantation times. The spike amplitude decreases over time of implantation, leading to poorer identification of neural signals. The effect of degradation on the local field potential detection is neglectable. This work could guide the reliability improvement of the neural electrodes.