Quantum Tunneling Composite (QTC) based tactile sensor array for dynamic pressure distribution measurement

This paper presents the design and simulation of a quantum tunneling composite (QTC) based tactile sensor array for use in pressure distribution measurement. QTC exhibits a rapid reduction in resistance with applied force making it suited for use in force sensing applications. Properties of QTC are exploited to design a tactile sensor array capable of measuring a dynamic pressure distribution over the sensor area. QTC acts a complete conductor after a certain stage reducing its effectiveness as a force sensor beyond that stage. QTC also takes considerable time to return to its original state after deformation due to force. These drawbacks found in QTC, limits its use to only that of a simple low cost switch. The proposed design for the tactile sensor array overcomes these drawbacks found in QTC material by incorporating a novel sensor array structure which enables an extended range of operation and allows rapid return to its unloaded state. This design allows for the use of QTC as a simple, cheap force sensor. The design can be further optimized to match the characteristics of the proposed sensor with the force range of a given application. A collection of such tactile elements is used to create a dynamic force sensing array. The design and simulation of the sensor array structure is described. This sensor array can be connected via a data acquisition system to a computer, which converts the data into a color contour map using LabView and MATLAB to measure and display the force distribution in realtime.