I am trying to increase the working bandwidth of the energy harvester by incorporating the stopper so that with the restricted motion there should be increase in the bandwidth. I am using comsol multiphyics software to achieve it. I am trying to set up the model as it is previously done in the different paper but I am not able to achieve the same. SOme paper that able to incorporate is :" Liu, H.C.; Lee, C.; Kobayashi, T.; Tay, C.J.; Quan, C.G. A MEMS-based wideband piezoelectric energy harvester system using mechanical stoppers. In Proceedings of the 2011 IEEE International Electron Devices Meeting, Washington, DC, USA, 5–7 December 2011."