Resolution and precision measurement of a three dimension force sensor based on piezoresistive conductive ink

In order to achieve the function of measuring friction on contacting surface between wafer and manipulator in real time, in this paper, we mainly measured the resolution and precision of the three dimension force sensor based on piezoresistive conductive ink. Resolution of tangential force improves with preload in normal direction increasing and the maximum resolution is less than 0.025 N with 0.8 N preload. Maximum error is about 30.62% because of low tangential stiffness of elastomer. The experiment results indicate that this sensor has characteristics of small volume, high flexibility and high resolution, which is prospective for using in wafer transfer system with improvement of higher precision in the future.