Design and fabrication of a thin and soft tactile force sensor array based on conductive rubber

Purpose - The purpose of this paper is to provide a thin tactile force sensor array based on conductive rubber and to offer descriptions of the sensor design, fabrication and test. Design/methodology/approach - The sensor array consists of a sandwich structure. Sensing elements are distributed discretely in the sensor. Each sensing element has two electrodes and a piece of conductive rubber with piezoresistive property. The electrodes, as well as the conductive trace for signal transmission, are printed on the substrate layer by the screen printing technique. A scanning circuit based on zero potential method and an experimental set-up based on balance to characterize the sensor array are designed and implemented in the test of the sensor array. Findings - Experimental results verify the validity of the sensor array in measuring the vertical tactile force between the sensing elements and the object. Research limitations/implications - In this paper, all the sensors are tested without calibration procedures and the procedure of the dynamic test is implemented by manual operation. Practical implications - The sensor array could be applied to measure the plantar force for gait detection in clinical applications. Originality/value - The paper presents a tactile force sensor array with discrete sensing elements to essentially restrict the cross-talk among sensing elements. This paper will provide many practical details that can help others in the field.