High Precision and Low Force Resonant Probe Based on Quartz Tuning Fork

To realize the high-precision three-dimensional (3D) measurement of micro-precision devices, a 3D resonant trigger probe based on quartz tuning fork for micro/nano coordinate measuring machine (CMM) is proposed. The probe is composed of a quartz tuning fork, a tapered optical fiber stylus and a microsphere. It vibrates in resonance state and makes contact with the measured surface in the Z direction in tapping mode, while in the X and Y directions, it operates in friction mode. The 3D nano-positioning of the probe is achieved by the changes in resonance parameter caused by the interatomic force between the microsphere and the surface of the measured sample. In this study, the diameter of the probe microsphere can be as low as 80 & mu;m, and the length of the probe stylus is approximately 5 mm. The trigger resolution of the probe in the X, Y and Z directions are 0.44, 0.41 and 0.34 nm, respectively. The probing forces in the X, Y and Z directions are 2.25, 1.81 and 4.24 & mu;N, respectively. Experimental results verify that the proposed probe has the advantages of small size, sub-nano resolution and very low probing force. This probe can be used as the trigger probe of micro/nano CMM, which can be triggered by interatomic force.