Paired vibratory stimulation for haptic feedback

In this paper, we show a haptic feedback method named "Paired Vibratory Stimulation." We use two vibrators, one is attached onto the device and the other one is attached onto the fingernail. When the two vibrators are activated with different but close frequency, the beat vibration occurs only when the finger touches the device. A human can feel the beat vibration even when each original vibration is hard to be perceived. Therefore, the system can give vibratory sensation only at the contact area by using two vibrators. This is suitable for haptic feedback for a handheld mobile device. For the handheld device, sensation only arises at the contact area not at the holding hand or at the fingernail. This is also applicable to human skin interface system. Recently some researchers have proposed the systems which take advantage of human skin surface as an input media. Our method is suitable to give vibratory haptic feedback for that situation. We show our experimental results which clarified that the Paired Vibratory Stimulation can be achieved and applied to the human skin interface system.