This paper presents a novel design of a piezoelectric cantilever beam for energy harvesting applications. Finite element simulations have been carried out to evaluate the effect of variation of geometrical parameters on the generated voltage output. The effect of thickness and area of the designed piezoelectric structures on the output voltage has been investigated for different piezoelectric materials to select the optimal material for low-power applications. The simulation results have revealed the Aluminum nitride and PZT-7A as potential materials for PEH devices due to a higher output voltage generation (30–35 V) capability. The results have showcased the appropriate selection of piezoelectric materials. It has been demonstrated that the geometrical parameters of the beam have a substantial effect on the output voltage generation of PEH. In addition to the Finite element simulation-based design, an energy management strategy has been implemented to optimize the battery charging/discharging process. An IoT system with sensors has been proposed to monitor the real-time battery conditions and manage the output voltage generation of PEH. The designed system can optimally maintain the healthy charging voltage of the battery in the range of 3.6–3.7 V without overheating. The results from the simulation of the energy management system have showcased the capability to deliver a load of up to 0.05 watts suitable for low-power sensing applications.