Electro-Mechanical Characterization and Modeling of a Broadband Piezoelectric Microgenerator Based on Lithium Niobate

Namanu Panayanthatta (1) , Giacomo Clementi (2) , Merieme Ouhabaz (2) , Samuel Margueron (2) , Ausrine Bartasyte (2, 3) , Mickael Lallart (4) , Skandar Basrour (5) , Roberto La Rosa (6) , Edwige Bano (1) , Laurent Montes (1)

1 CROMA - Centre de Radiofréquences, Optique et Micro-nanoélectronique des Alpes
2 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
3 IUF - Institut universitaire de France
4 LGEF - Laboratoire de Génie Electrique et Ferroélectricité
5 TIMA-CDSI - Circuits, Devices and System Integration
6 ST Microélectronics

Vibration energy harvesting based on piezoelectric transducers is an attractive choice to replace single-use batteries in powering Wireless Sensor Nodes (WSNs). As of today, their widespread application is hindered due to low operational bandwidth and the conventional use of lead-based materials. The Restriction of Hazardous Substances legislation (RoHS) implemented in the European Union restricts the use of lead-based piezoelectric materials in future electronic devices. This paper investigates lithium niobate (LiNbO3) as a lead-free material for a high-performance broadband Piezoelectric Energy Harvester (PEH). A single-clamped, cantilever beam-based piezoelectric microgenerator with a mechanical footprint of 1 cm2, working at a low resonant frequency of 200 Hz, with a high piezoelectric coupling coefficient and broad bandwidth, was designed and microfabricated, and its performance was evaluated. The PEH device, with an acceleration of 1 g delivers a maximum output RMS power of nearly 35 μW/cm2 and a peak voltage of 6 V for an optimal load resistance at resonance. Thanks to a high squared piezoelectric electro-mechanical coupling coefficient (k2), the device offers a broadband operating frequency range above 10% of the central frequency. The Mason electro-mechanical equivalent circuit was derived, and a SPICE model of the device was compared with experimental results. Finally, the output voltage of the harvester was rectified to provide a DC output stored on a capacitor, and it was regulated and used to power an IoT node at an acceleration of as low as 0.5 g.

Mots clés: piezoelectric energy harvester; lithium niobate; lead-free piezoelectrics; IoT; broadband energy harvesting

Domaines: Sciences de l'ingénieur [physics]

Namanu Panayanthatta, Giacomo Clementi, Merieme Ouhabaz, Samuel Margueron, Ausrine Bartasyte, et al.. Electro-Mechanical Characterization and Modeling of a Broadband Piezoelectric Microgenerator Based on Lithium Niobate. Sensors, 2024, 24 (9), pp.2815. ⟨10.3390/s24092815⟩. ⟨hal-04568043⟩