Non-contact characterisation of piezoelectric materials

Alexandrou, Anna; Fotouhi, Sakineh; Nelson, James; Cochran, Sandy

Abstract

Piezoelectric materials play a key role in various technological applications owing to their unique elastic-piezoelectric-dielectric (EPD) properties, often represented in matrix form. Traditional methods for obtaining these properties, as defined by IEEE standards, rely on Electrical Impedance Spectrometry (EIS) of various samples, some with high aspect ratios, to permit the analysis of individual electroacoustic modes. Combining all outcomes allows the extraction of the EPD matrix. Nevertheless, the requirement of multiple samples yields high cost due to manufacture and discrepancies between different samples. This, in combination with sample contact requirements, are impractical in many cases where materials are needed to be tested under elevated temperature and pressure conditions. With continuous demand for new piezoelectric materials, an alternative approach has been studied utilising only single samples, usually a cube of side several mm. This method combines EIS, Resonant Ultrasound Spectroscopy (RUS) and an optimisation algorithm to extract independent properties within the EPD matrix. Although this eliminates the need for multiple samples, it still necessitates physical contact with the sample, while RUS brings additional measurement inaccuracies due to difficulties in thick sample preparation and poling. This study discusses the potential of a non-contact, approach for characterising piezoelectric materials. The proposed methodology utilises a high-power laser to generate ultrasound waves within a compact, single, 1 mm3 cube sample. The resulting vibrations at various points on the sample’s surface are detected using a laser Doppler vibrometer (LDV) with post processing of the measurements through an optimisation package required to extract specific piezoelectric properties. The present study is at early stage, with equipment assembled and preliminary results obtained through finite element analysis. Future work is required to determine the feasibility of extracting the full EPD matrix for different types of piezoelectric materials. This research represents a further step towards advancing the characterization of piezoelectric materials under simulated operating conditions, paving the way for more efficient and accurate assessments in a wide range of applications.

• Presentation Conference Type: Poster
• Conference Name: Electroceramics for End Users XII (ECEUXII)
• Start Date: Nov 5, 2023
• End Date: Nov 8, 2023
• Deposit Date: Jan 8, 2024
• Public URL: https://uwe-repository.worktribe.com/output/11459706
• Publisher URL: https://www.gla.ac.uk/s...ch/conferences/eceuxii/