In this study we present a two-dimensional force sensor based on a single long-period fiber grating (LPG) to be applied to robotic manipulators grasping control. The measuring force is applied to the fiber transverse section and this lateral compression induces birefringence on the fiber, which splits the LPG resonant dip into two. We track these dips using polarized controlled light and process the LPG spectra using artificial neural networks to determine the force intensity and direction. Finally, our single sensor proposal for 2D forces measurement can estimate an applied force with 0.2148 N and 5.977 deg. error.