Micro-force measurement with pre-curvature long-period fiber grating-based sensor Walter S. J. Ferreira, Paulo S. S. dos Santos, Paulo Caldas, Pedro A. S. Jorge and João M. S. Sakamoto EPJ Web Conf., 238 (2020) 12009 Published online: 20 August 2020 DOI: 10.1051/epjconf/202023812009