Tactile Pressure Sensors

Tactile pressure sensors are used to measure stresses at the interface between the soil and a structural element (e.g., foundation, retaining wall). They consist of two flexible polyester sheets attached to each other, which contain thin stripes of pressure sensitive conductive ink. The resulting grid of stripes is surrounded by a semi-conducting substance and constitutes the “matrix”, i. e. the active measuring area of the sensor. The available tactile sensors at the GCC are manufactured by Tekscan Inc. For example, the I-Scan5051 sensor incorporates 1936 sensing elements (mesh nodes) in an area of 55.9 x 55.9 mm, offering a spatial density of 0.79 nodes/mm2. The tactile sensor has been extensively used with good repeatability in the ETHZ geotechnical centrifuge (Laue et al. 2002; Springman et al. 2002; Laue & Springman 2003).