Studies on human patients have allowed better understanding of the conscious sensations associated with ICMS (intracortical microstimulation) in hopes of restoring sensory functions. An effective clinical neuro- prosthetic should manipulate neural activity at a high spatial resolution, minimize charge injection, and demonstrate chronic stability. In this thesis, we propose that the Stimulating NanoElectronic Threads (StimNETs) possess these attributes by examining and providing experiment evidence for the following three research goals: (1) Using two-photon (2P) calcium imaging of awake animals, we visualized and verified selective neuronal activation patterns under low-current ICMS. (2) To evaluate the behavioral effects of ICMS, we designed a go/no-go detection threshold task and observed thresholds as little as 0.25 nC/phase. (3) To show that stim-NETs are chronically stable, we present longitudinal data with the longest behavioral performing animal 10 months post-implantation. These results show that tissue-integrated ultraflexible electrodes provide high-resolution, efficacy, and stability in neuromodulation.