Transparent and Highly Voltage-controllable Electro-tactile Actuator

Tactile sensation plays key roles in the realization of senses of prosthetics, virtual reality (VR), augmented reality (AR), and display touch panels. In recent years, vibro-tactile technology was dominant in this field of research. However, until now, most vibro-tactile devices have critical limitations to provide a variety of sensations and stimulation in close intervals due to their bulky forms. Therefore, electro-tactile device is a promising candidate for a tactile stimulation system. Herein, we demonstrate a transparent, voltage-controllable electro-tactile actuator capable of presenting a variety of senses and high-resolution tactile information of 2 mm. This electro-tactile actuator is advantageous to control the frequency, amplitude, and pulse width of applied electrical pulses to different mechanoreceptors. We exhibited the effectiveness of this actuator through cognitive experiments on human subjects and neuronal signals from the fingertips to the brain. Through the cognitive experiments, 10 subjects detected stimulation at a low voltage on the fingertip electro-tactile device (<10 V), and it was possible to cause a large range of senses such as vibration, tapping, hardness, and pain by varying stimulation frequency (10-300 Hz). Pulse signals transmitted into the skin through an actuator were also measured as neuronal signals. This electro-tactile actuator is expected to work in many fields, including transparent mobile displays, artificial prosthetics, or even VR and AR tactile displays due to its accuracy in local stimulation, and high transparency.