Flexoelectric effect in functionally graded materials: A numerical study Anuruddh Kumar, Raj Kiran, Rajeev Kumar, Satish Chandra Jain and Rahul Vaish Eur. Phys. J. Plus, 133 4 (2018) 141 Published online: 11 April 2018 DOI: 10.1140/epjp/i2018-11976-1