Online Pressure Map Reconstruction in a Multitouch Soft Optical Waveguide Skin

In this article, we present a reconstruction method for mapping a wide range of pressure stimuli in a multitouch soft optical waveguide skin (MSOWS). Distributed sensing information is typically obtained from wired soft sensing units. This approach hardly adapts to different shapes and has limited durability against stresses and shocks. In our MSOWS, the spatial tactile transduction relies on a continuum sensitive area of graded-stiffness polydimethylsiloxane, with a virtual grid free from electronics and connections. The sensing range of each cell is up to 234 kPa, and the spatial resolution is 5 mm. We use a time-delay neural network to reduce the hysteresis of the soft material to less than 1%. In addition, a fault-tolerant mechanism makes the entire system robust to component failure. These results may open the way to a new generation of distributed soft skins that are versatile due to material design and processing.