Toward Flexible Piezoelectrets with High Environmental Stability: A Hybrid Approach

Zhe Liu1,2  

Min Zeng3  

Hui Wang1,2  

Xiaolin Wang1,2  

Yan Li1,2 

Changchun Zeng1,2,*Email

High-Performance Materials Institute, Florida State University, Tallahassee, FL, 32310, USA

Department of Industrial and Manufacturing Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, 32310, USA

Nanjing Polytechnic Institute, No.625, Geguan Road, Dachang, Luhe District, Nanjing City, Jiangsu Province, 210048, China

Abstract

In this work an effective and low-cost method to fabricate hybrid piezoelectrets based on cyclic olefin copolymer (COC) and polypropylene (PP). The electromechanical properties of the hybrid piezoelectrets were characterized. In the hybrid piezoelectrets, PP constituted the overall structure while COC was used as surface layers for charge storage. The hybrid piezoelectrets exhibited good piezoelectric properties, flexibility, and significantly improved environmental stability. The hybrid piezoelectrets had a piezoelectric coefficient d33 up to 1200 pC/N. The PP piezoelectrets lost all piezoelectric activity after annealing for 16 hours at 70°C. By comparison, even after 200 hours of annealing at 110°C, the hybrid COC/PP piezoelectrets still retained 25% of the activity. The hybrid piezoelectrets also showed excellent stability under high humidity. The performance of the hybrid piezoelectrets as force sensors were demonstrated.