We report on our development of sensorized fingernails for mechatronical hands. Our proposed design can capture static and dynamic interaction forces with the nail and provide basic information about the direction of the main force vector. Over the course of several iterations, we have developed a very compact working prototype that fits together with our previously developed multi cell MID-based tactile fingertip sensor into the cavity of a finger of a Shadow Robot Hand, a robotic hand roughly the size of an average male hand. High sensitivity combined with robustness for daily use are the key features describing our proposed design.