High-Voltage Synchronous Electric Charge Extraction for Piezoelectric Energy Harvesting in Smart Tires

Growing demand for safer and energy efficient vehicles is driving the development of advanced sensors, such as smart tires capable of sensing multiple parameters and processing data locally. However, this leads to increased energy requirements, incompatible with batteries of conventional tire pressure monitoring systems (TPMS). Strain energy harvesting offers a viable approach to harness the forces acting on tires. This article presents a complete energy harvesting solution for sustainable battery-less operation of automotive Bluetooth smart tire sensors. High-voltage synchronous electric charge extraction (HV-SECE) from flexible PVDF transducers is proposed, modeled in overdamped regimes, and validated for the first time in a realistic automotive scenario. The proposed HV-SECE circuits can manage input voltages up to 300 V and provide a 3 V regulated voltage in a minimum footprint area down to 22 × 20 × 7.3 mm. At 40 km/h, in 205/55-R16 tires, the maximum harvested power from 10 × 5 cm bimorphs made with 45 µm-thick PVDF foils amounts to 925 µW. Even at low speeds, HV-SECE interfaces can cold-start the wireless tire sensor in less than 60 s, faster than regulatory TPMS requirements, and ensure energy surplus.