A sandwiched piezoelectric transducer with flex end-caps for energy harvesting in large force environments. (1st August 2017)

• Record Type: Journal Article
• Authors: Kuang, Yang; Daniels, Alice; Zhu, Meiling
• Is Part Of: Journal of physics. Volume 50:Number 34(2017)
• Publication Date: 2017-08-01
• Subjects: piezoelectric energy harvesting -- sandwiched piezoelectric transducer -- cymbal transducer -- wearable energy harvesting -- shoe energy harvesting; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aa7b28
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: This paper presents a sandwiched piezoelectric transducer (SPT) for energy harvesting in large force environments with increased load capacity and electric power output. The SPT uses (1) flex end-caps to amplify the applied load force so as to increase its power output and (2) a sandwiched piezoelectric-substrate structure to reduce the stress concentration in the piezoelectric material so as to increase the load capacity. A coupled piezoelectric-circuit finite element model (CPC-FEM) was developed, which is able to directly predict the electric power output of the SPT connected to a load resistor. The CPC-FEM was used to study the effects of various parameters of the SPT on the performance to obtain an optimal design. These parameters included the substrate thickness, the end-cap material and thickness, the electrode length, the joint length, the end-cap internal angle and the PZT thickness. A prototype with optimised parameters was tested on a loading machine, and the experimental results were compared with simulation. A good agreement was observed between simulation and experiment. When subjected to a 1 kN 2 Hz sinusoidal force applied by the loading machine, the SPT produced an average power of 4.68 mW. The application of the SPT as a footwear energy harvester was demonstrated by fitting the SPT into a boot and performing the tests on a treadmill, and the SPT generated an average power of 2.5 mW at a walking speed of 4.8 km h −1 .