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

Meriam Ben Ammar; Salwa Sahnoun; Ahmed Fakhfakh; Christian Viehweger; Olfa Kanoun

doi:10.3390/s23041830

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

Sensors (Basel). 2023 Feb 6;23(4):1830. doi: 10.3390/s23041830.

Authors

Meriam Ben Ammar^{1

2

3}, Salwa Sahnoun^{2

3}, Ahmed Fakhfakh^{2

3}, Christian Viehweger¹, Olfa Kanoun¹

Affiliations

¹ Measurements and Sensor Technology, Faculty of Electrical Engineering and Information Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany.
² National School of Electronics and Telecommunications of Sfax, University of Sfax, Sfax 3038, Tunisia.
³ Laboratory of Signals, Systems, Artificial Intelligence and Networks, Digital Research Center of Sfax, University of Sfax, Sfax 3038, Tunisia.

Abstract

Piezoelectric Vibration converters are nowadays gaining importance for supplying low-powered sensor nodes and wearable electronic devices. Energy management interfaces are thereby needed to ensure voltage compatibility between the harvester element and the electric load. To improve power extraction ability, resonant interfaces such as Parallel Synchronized Switch Harvesting on Inductor (P-SSHI) have been proposed. The main challenges for designing this type of energy management circuits are to realise self-powered solutions and increase the energy efficiency and adaptability of the interface for low-power operation modes corresponding to low frequencies and irregular vibration mechanical energy sources. In this work, a novel Self-Powered (SP P-SSHI) energy management circuit is proposed which is able to harvest energy from piezoelectric converters at low frequencies and irregular chock like footstep input excitations. It has a good power extraction ability and is adaptable for different storage capacitors and loads. As a proof of concept, a piezoelectric shoe insole with six integrated parallel piezoelectric sensors (PEts) was designed and implemented to validate the performance of the energy management interface circuit. Under a vibration excitation of 1 Hz corresponding to a (moderate walking speed), the maximum reached efficiency and power of the proposed interface is 83.02% and 3.6 mW respectively for the designed insole, a 10 kΩ resistive load and a 10 μF storage capacitor. The enhanced SP-PSSHI circuit was validated to charge 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 proposed energy management interface has a cold start-up ability and was also validated to charge a (65 mAh, 3.1 V) maganese dioxide coin cell Lithium battery (ML 2032), demonstrating the ability of the proposed wearable piezoelectric energy harvesting system to provide an autonomous power supply for wearable wireless sensors.

Keywords: energy management; footsteps; human motion; piezoceramics; piezoelectric energy harvesters; piezoelectric insole; power supply; rectifiers; self-powered; synchronized switching; vibration; wearable energy harvester; wearables.

Grants and funding

This research was supported by the German Academic Exchange Service (DAAD) by funds from the Federal Ministry for Economic Cooperation and Development (BMZ) Germany, within the project number #57505087.