Positional feedback of a linear track slider using a low-cost stretch sensor

Abstract

The artificial muscles of a biomimetic model of the human stomach require positional control of the (linear track) sliders that the actuated muscles are attached to. A novel servomechanism for positional control of a slider on a linear track has been explored using a basic, low -cost stretch sensor as a means in determining the sliders' absolute position over time. The stretch sensor was constructed from a silicone (PDMS) tube filled with an ionic liquid (saline) and exhibited good characteristics of linearity and low hysteresis. A micro controller was used for conditioning the sensor feedback and software control over the slider positioning. Initial results indicate a coarse approximation is attainable of the slider position relative to its targeted position. However, further testing is required to determine operational life-time and other factors such as repeatability, drift and potential for improved accuracy.