This paper mainly concerns a vibrotactile sensor capable of generating impulsive high-frequency signals for exclusively distinguishing a slip phase from various other contact phases. We describe the structure of the vibrotactile sensor with surface ridges and, after analyzing the slip signals, conclude that the output signal originates in the free vibration of the ridge. By using a two-fingered robot hand with the sensor attached to its compliant endtips, we verify that the vibrotactile sensor has a slip phase isolating function and demonstrate object regrip control in real time.