Recent advancements in energy harvesting have enabled the development of technologies capable of converting ambient energy into usable electrical power. This study explores the feasibility of using piezoelectric nanogenerators to harness vibrational energy from both voluntary and involuntary hand movements, with a focus on essential tremors. A vertically integrated ZnO-based nanogenerator was modeled and simulated using COMSOL Multiphysics, specifically optimized for the low-frequency range of hand tremors (8–12 Hz). The simulation results revealed a maximum voltage output of 0.343 V under a mechanical load of 100 nN, demonstrating the nanogenerator's high sensitivity to mechanical stress and its capacity to efficiently convert low-frequency vibrations into electrical energy. This outcome highlights the potential application of the nanogenerator for powering self-sustained smart wearables and medical devices, particularly for individuals with tremor conditions. These findings mark a significant advancement in integrating piezoelectric energy harvesting technologies with healthcare applications, paving the way for more efficient, self-powered medical devices.