Single element based tactile display

This work describes the design and performance of a single element tactile display using shape memory alloy wire (SMA) as an actuator which when pulsed with an electrical current (in effect heating the metal), can be raised and lowered to approximate the desired output signal. The system is designed in order to obtain a linear approximation between displacement and resistance as well as the necessary A/D conversion, and the pulse width modulation (PWM) control of thhe wire through its electroni circuitry using a PIC Micro-controller 16C74A used to perform all the necessary control. The paper also focuses on the ability to stimulate the perception experienced from the operator´s fingertip and to provide a sensation of touch or force. This work presents a means by which the system can be developed further so that such devices could be used to explore objects in virtual environment and act as input device to CAD tools.