2-D and 3-D tactile pin display using SMA micro-coil actuator and magnetic latch

A 2D and 3D tactile pin display has been fabricated and developed. Character and graphic information are dynamically displayed by making the pin array move up and down. Shape memory alloy (SMA) micro-coil actuators contract and make the pins move up and down when the SMA actuator is heated by supplying electrical current. A magnetic material tube is attached to each pin and a permanent magnet fixes the position of the pins´ up or down state. The mechanism solves problems of heat storage and electrical consumption of the SMA actuator because the current is supplied only when the pins move. A 2D tactile pin display which has a 100 (10×10) pin array has been developed and successfully operated. The tactile information is displayed sequentially every 0.3 sec and the pins are latched at 0.1 N by magnetic force. The pins are arranged at a pitch of 2.5 mm and move 2 mm up and down. A multi-step magnetic latch has been developed for a 3D expression. By using these mechanisms, several types of tactile information, e.g. 2D, 3D, dynamic motions, can be easily displayed.