Evaluating the addition of piezoelectric polymer in UV curable resin for 3D printing using digital light projection

Abstract

Fascination with smart materials, such as piezoelectric materials, and its broad range of possible applications have driven efforts in research to develop better techniques to fabricate them. 3D printing is one form of additive manufacturing technique which has proved to be a quick and budget-friendly option for manufacturing parts. For the Digital Light Projection (DLP) technique specifically, its advantage lies in producing printed parts of superior surface finish and better resolution than other 3D printing techniques. As for piezoelectric materials, Polyvinylidene Fluoride (PVDF) is a widely available piezoelectric polymer with good piezoelectric performance and can be potentially produced using the DLP technique. DLP-printed PVDF structures display immense potential in a myriad of applications. Potential applications commonly mentioned in various literature include energy harvesting devices, soft robotics and biomedical devices. This paper sought to investigate the printability, mechanical properties and piezoelectric performance of samples with varying formulations containing PVDF. Cure depth tests, tensile tests and piezoelectric effect tests were conducted to fill the information gaps and further validate the possibility of using DLP-printed piezoelectric polymers in soft robotics and prosthetics. In this study, it was found that generally, increasing PVDF concentrations improved (1) the curing characteristics, (2) the mechanical properties and (3) the piezoelectric performance of the DLP-printed samples. Therefore, for DLP-printed PVDF polymer composites to fulfil their potential in various novel applications, it is advantageous for the PVDF content to be as high as possible. However, there are still several unanswered questions about the microscopic effects of adding PVDF in the formulations and the dimensional accuracy of the printed parts. Thus, future studies on these topics are recommended.