Position control of SMA actuator for 3D tactile display

The purpose of this study is to design and fabricate an actuator system for a 3D tactile display. Small size actuator or portable actuator has many possible applications in medicine and industry. In the past, motors have been widely used to create motion in large-area tactile displays. Thus, the device discussed in this paper uses shape memory alloy (SMA) which allows us to create a small, lightweight and high-resolution tactile display. However, there are also challenges using SMA as actuator. The nonlinear hysteresis properties of the SMA cause difficulties during the control of the display. Our design is an 8times8 display consists of 64 SMA springs to create motion for 64 pin display. Each of the pin display takes approximately 0.4 seconds to response to the input. The pin displacement can travel up to 25 mm.