Flexoelectric effect in functionally graded materials: A numerical studyAnuruddh Kumar, Raj Kiran, Rajeev Kumar, Satish Chandra Jain and Rahul VaishEur. Phys. J. Plus, 133 4 (2018) 141DOI: https://doi.org/10.1140/epjp/i2018-11976-1