A new micro/nano displacement measurement method based on a double-fiber Bragg grating (FBG) sensing structure

Abstract

The trend toward miniaturization in manufacturing has led to a requirement for micro/nano measuring techniques capable of measuring tiny features on small components. In this paper we propose and demonstrate a novel scheme for micro/nano displacement measurement based on a double-FBG (fiber Bragg grating) sensing structure, a suspended FBG probe stem and a fiber fused micro-ball tip. Such a scheme has some advantages including robustness, sensitivity, small size with large aspect ratio attainable, simplicity and economy. The preliminary experiments showed that the prototype yielded a measurement resolution of 10 nm and a nonlinear error of 150 nm.

A long-stroke 3D contact scanning probe for micro/nano coordinate measuring machine

“…The probe has a stiffness of 20 mN/mm and its repeatability is claimed to be 5 nm. The fourth kind is the fiber probe with a few position detectors [6,[13][14] or Bragg gratings [15][16][17]. The former one has an especially long probe shaft and a low contact force, but the precision cannot be in nanometer range because the probing system uses an image sensor or a position sensitive detector.…”

A temperature-insensitive FBG displacement sensor with a 10-nanometer-grade resolution

“…The friction between the wedge-shaped slider and the T-shaped cantilever beam at the slope reduces its reliability, especially when the gradient of the slope is large. References [19][20][21] used the FBG itself as the probe to test the displacement, which can achieve 10-nanometer-grade displacement measurement, but they are fragile, temperature sensitive, and have a poor environmental adaptability. Based on the references [16][17][18], the proposed sensor also bonded the two ends of the FBG and using the FBG itself as the elastic sensing element to avoid gluing the FBG area.…”

“…Comparing with references [16][17][18], the proposed sensor avoid the wedge-shaped slider structure, and can achieve a better repeatability and reliability. Comparing with the displacement sensors that use the FBG as the probe in references [19][20][21], the sensor proposed in the paper can achieve the same level (10-nanometer-grade) micro-displacement measurement with temperature compensation, and has a stronger environmental adaptability. To compare the performances of these sensors, resolution (or sensitivity) -measurement range ratio and sensor size are also important factor.…”

A 3D fiber probe based on orthogonal micro focal-length collimation and fiber Bragg grating

“…This probe is sensitive with axial loading, but lacks sensitivity along the radial direction. Cui proposed in 2014 a FBGbased double fiber probe [21], and first made a FBG-based probe which is sensitive to a radial contact displacement [22], but it still has a shortcoming in the radial resolution.…”