Check out these 2 post doc positions in the fields of bioelectronics and biomaterials:
https://www.researchgate.net/job/938746_Postdoctoral_position_in_NeuroEngineering_Nanobiomaterials_and_Bio-electronics_CB_77375
https://www.researchgate.net/job/938745_Postdoctoral_position_in_multiphysics_computations_for_biophotonics_and_nano-optics_CB_BDCNEW140