Design and simulation of 1-DOF tactile sensor for gripping force measurement

This paper presents the design and simulation of a quantum tunneling composite (QTC) based tactile sensor structure for gripping force measurement. The design presents a tactile sensing element capable 1-DOF force sensing in the z-direction. QTC is a novel electrically conductive elastomeric matrix-nanostructured nickel powder composite. QTC has extremely large, reversible increases in conductivity when compressed, stretched, bent, or twisted. These properties are exploited to design a tactile sensor capable of measuring a dynamic force over the sensor area. QTC has some drawbacks which have limited its use to a simple pressure switch. One drawback of QTC is that it acts as a complete conductor beyond a certain stage of compression. Another is that it takes considerable time to return to the initial shape after compression. The proposed sensor design is able to overcome these drawbacks by extending the range of operation of QTC and rapidly returning the QTC to its unloaded shape. 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. The design and simulation of the sensor structure is described. This sensor is to 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 pressure distribution in real-time.