Microneedle-based electrodes with integrated through-silicon via for biopotential recording

The fabrication of a novel ultrasharp silicon microneedle array for use as a physiological signal monitoring electrode is described. This work uses anisotropic potassium hydroxide wet etching and double-sided wafer patterning to simultaneously create a microneedle on the front side of the wafer, and a through-silicon via from the back side. This technique eliminates the limitations associated with other approaches that are used to create front-to-back electrical contact. Wearable electrode prototypes have been assembled using these arrays, and electrocardiography (ECG) recordings have been carried out to verify the functionality of the technique.