Flexible Electrode for Implantable Neural Devices

The function of neural electrodes is to interface with the neural system for both sensory and actuation purposes. One of the major challenges in neural devices is to achieve a precise and reliable neuron–electrode interface (NEI). Advances in microfabrication technologies create the possibility to increase the number and reduce the size of electrode sites which can improve the spatial resolution of the NEI. Alternatively, replacing the substrate material of the microfabricated neural electrode from the rigid silicon to the flexible polymer can minimize the stiffness mismatch between electrodes and neural tissue, thus potentially improving the reliability of NEI. In this chapter, we provide an overview of the recent development in microfabricated polymeric neural electrodes. At first, we give a summary of material properties and fabrication processes for some polymers commonly used in the neural electrode application. Then, we review various designs of polymeric neural electrodes in the context of their specific applications. Finally, challenges and corresponding strategies in the development and practicability of polymeric neural electrodes are discussed. © Springer Science+Business Media New York 2014.1