High Output Tactile Display Using Sma Thick Film Actuator Array with Improved Thermal and Frequency Response

This paper reports a fabrication and characterization of micro electro mechanical systems (MEMS) tactile display with meandering-shaped shape memory alloy (SMA) thick film actuator and SU-8 micro-pin array (1.5mm pitch, 5×5). The design of the SMA actuator was thermally and mechanically modified to improve sufficient amplitude to present vibratory stimuli to the fingertip. The tactile display device has been successfully fabricated, and amplitude of 22 μm was obtained which greatly exceeded the detection threshold of fingertip when driven at 20Hz at which mechanoreceptor in human skin has high sensitivity and high in-plane resolution for stimulus detection. The results of simple sensory examination showed that the device could clearly present vibrational stimulation to human fingertip at a driving frequency of 20 Hz even though the vibration of one micro-pin.