Self-Powered Synchronized Switching Interface Circuit for Piezoelectric Footstep Energy Harvesting

Area of Science:

• Energy Harvesting
• Materials Science
• Electrical Engineering

Background:

• Piezoelectric vibration converters are crucial for powering low-power sensor nodes and wearable devices.
• Energy management interfaces are essential for voltage compatibility between harvesters and loads.
• Resonant interfaces like Parallel Synchronized Switch Harvesting on Inductor (P-SSHI) improve power extraction but face challenges in self-powered, efficient, and adaptable low-power operation.

Purpose of the Study:

• To propose a novel Self-Powered (SP P-SSHI) energy management circuit for piezoelectric converters.
• To enhance energy harvesting efficiency and adaptability for low frequencies and irregular vibrations.
• To demonstrate the circuit's capability in powering wearable electronic devices.

Main Methods:

• Development of a Self-Powered (SP P-SSHI) energy management circuit.
• Implementation of a piezoelectric shoe insole with six integrated piezoelectric sensors (PEts) as a proof of concept.
• Validation of the circuit's performance under low-frequency (1 Hz) vibration excitation.

Main Results:

• The proposed SP P-SSHI circuit achieved a maximum efficiency of 83.02% and power of 3.6 mW for a piezoelectric shoe insole at 1 Hz.
• The circuit demonstrated adaptability by charging a 10 μF capacitor to 6 V in 3.94 s and a 1 mF capacitor to 3.2 V in 27.64 s.
• The system successfully charged a ML 2032 lithium battery, proving its potential for autonomous power supply in wearable sensors.

Conclusions:

• The novel SP P-SSHI circuit offers efficient and adaptable energy harvesting from low-frequency and irregular vibrations.
• The piezoelectric shoe insole system demonstrates the practical application of the circuit for powering wearable wireless sensors.
• The developed system provides a viable solution for autonomous power supply in wearable electronics.