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.
View Article and Find Full Text PDFMicrofabrication procedure of piezoelectric micro electro-mechanical systems based on 5m thick LiNbOfilms on SiO/Si substrate at wafer scale including deep dry etching of thick LiNbOfilms by implementing pulsed mode of Ar/SFgas was developed. In particular, two (YXlt)/128°/90°LiNbO-Si cantilevers with tip mass were fabricated and characterized in terms of resonance frequency (511 and 817 Hz), actuation and acceleration sensing capabilities. The quality factor of 89.
View Article and Find Full Text PDFIn this paper, we present integrated lead-free energy converters based on a suitable MEMS fabrication process with an embedded layer of LiNbO. The fabrication technology has been developed to realize micromachined self-generating transducers to convert kinetic energy into electrical energy. The process proposed presents several interesting features with the possibility of realizing smaller scale devices, integrated systems, miniaturized mechanical and electromechanical sensors, and transducers with an active layer used as the main conversion element.
View Article and Find Full Text PDFWireless sensor nodes (WSNs) are the fundamental part of an Internet of Things (IoT) system for detecting and transmitting data to a master node for processing. Several research studies reveal that one of the disadvantages of conventional, battery-powered WSNs, however, is that they typically require periodic maintenance. This paper aims to contribute to existing research studies on this issue by exploring a new energy-autonomous and battery-free WSN concept for monitor vibrations.
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