This paper presents Smart Energy Wheels, a comprehensive piezoelectric energy harvesting system designed for electric vehicles (EVs). Low-cost 35 mm PZT ceramic discs are embedded on the inner liner of the tire to convert cyclic mechanical deformation and road-induced vibrations into electrical energy via the direct piezoelectric effect. The generated AC voltage is conditioned through a full- bridge rectifier using 1N4007 diodes, stored in a supercapacitor (or electrolytic capacitor), and wirelessly transferred to the vehicle chassis using a 5 V 2 A inductive coupling module operating across a 3–10 mm air gap. Laboratory experiments under simulated wheel conditions (vibration frequencies of 5–20 Hz corresponding to vehicle speeds of 10–50 km/h) demonstrated an average power output of 0.08– 0.45 mW per disc and 1–5 mW per wheel with four discs in parallel. This harvested power is sufficient to drive auxiliary low-power systems such as Tire Pressure Monitoring Systems (TPMS), temperature sensors, vibration monitors, and wireless data transmitters. The wireless power transfer stage achieved 55– 78% efficiency under optimal alignment. The proposed system offers a maintenance-free, contactless, and eco-friendly solution for recycling otherwise wasted mechanical energy in EV tires, thereby enhancing overall vehicle efficiency and supporting sustainable mobility. Experimental results are consistent with contemporary literature while uniquely incorporating inductive wireless transfer for rotating wheel applications.

Index Terms—Piezoelectric energy harvesting, PZT sensors, electric vehicles, smart tires, wireless power transfer, inductive coupling, supercapacitor, sustainable transportation