Vibrational Braille code display with MEMS-Based hydraulic diplacement amplification mechanism

We demonstrate an efficient vibrational Braille code display with large-displacement MEMS actuator arrays. The large displacement is realized by hydraulic displacement amplification mechanisms (HDAM). Static and dynamic characteristics of HDAM were investigated and 18- and 11-fold amplification were achieved in static and dynamic (at 70 Hz) actuation, respectively. We applied actuator arrays consisting of HDAM and piezoelectric actuators to Braille code display. Owing to the characteristics of finger tactile receptors being more sensitive to vibrational stimuli than static ones and the natural frequency of HDAM, vibrational actuation at 70 Hz, which required a low voltage of 30V for subjects to detect the code, were more efficient than static actuation, which required 65V, and vibrational actuation at other frequencies.