Analysis, simulation, and experimental investigations of a one dimensional touch panel based on strain sensing

In this work, a 1-D touch panel based on strain sensing has been designed and realized as a preliminary test protocol for evaluating smart floor tiles concept used for indoor localization. By integrating the strain sensing technique and elementary beam theory, it is possible to estimate the force-applied location based on strain gauge outputs. Detail 3D finite element analyses have been conducted to evaluate the design concept and to quantify the influence of various possible practical considerations such as boundary conditions and sensor gain differences, as well as attachment and alignment errors during assembly. It is found that the 1-D beam design approach agrees with the 3D finite element simulations very well except the portions near both beam ends. The experimental results indicated that under an applied force of 1N, the effective zone is near 70% and the spatial resolution is between ±0.21 ∼ ±0.37 cm. This resolution is sufficient for a finger touch device and is much higher for smart floor applications. Currently, with the lesson learned, investigations on a 2D strain sensing panel is currently proceeded to serve as the basis for more realistic smart floor tile designs currently underway for smart building applications.