Measuring the interfacial stress between robots and objects is a prerequisite for robots to finish complicated works. In general, the interfacial stress is the 3-D interfacial stress which not only couple with the vertical normal interfacial stress but also the parallel shear interfacial stress. It is very important to develop a method to decouple the 3-D interfacial stress. This paper presents a measurement method that was able to decouple the measurement of the 3-D interfacial stress components. To implement the method, a 3-D interfacial stress sensor was fabricated based on graphene foams and superelastic materials. A high-resolution multichannel resistance measurement circuit was developed, and experiments were carried out with 3-D stress simulation equipment. The results showed that the sensor was capable of measuring z-direction normal stress at a range of 0–21 kPa with a sensitivity of 0.029 kPa−1 and x- and y-direction shear stresses at a range of 0–12.5 kPa with sensitivities of 0.020, 0.019, 0.018, and 0.019 kPa−1, and the measurement circuit was capable of measuring a range of $100,,Omega -100,,textsf {M}Omega $ with a resolution of 1%. This method can be utilized in robots to decouple the measurement of the 3-D interfacial stress components.
Published in: "IEEE Transactions on Electron Devices".