Surface effects on nonlinear dynamics of NEMS consisting of double-layered viscoelastic nanoplates Farzad Ebrahimi and S. H. S. Hosseini Eur. Phys. J. Plus, 132 4 (2017) 172 Published online: 14 April 2017 DOI: 10.1140/epjp/i2017-11400-6