Localized Stimulation of and Recording from Neural Cells with Fluid Injectable Neuronal Microneedles

A neuronal microneedle, a single-crystalline silicon microneedle with fluidic microchannels and microelectrodes, is developed for localized stimulation of and recording from neural cells. The neuronal microneedle delivers drugs such as excitatory amino acids at the cellular level as well as electrically records neural signals from neural cells. The fluidic behavior, the mechanical stability, and the electrode-electrolyte interface impedance of the fabricated neuronal microneedle were characterized, respectively. Then, the neural cell responses of a brain of a male Sprague-Dawley rat to a 25μM kainic acid (KA) stimulus were acutely monitored by using the developed neuronal microneedle.