Regular and chaotic vibration in a piezoelectric energy harvester with fractional damping Junyi Cao, Arkadiusz Syta, Grzegorz Litak, Shengxi Zhou, Daniel J. Inman and Yangquan Chen Eur. Phys. J. Plus, 130 6 (2015) 103 Published online: 02 June 2015 DOI: 10.1140/epjp/i2015-15103-8