A Single-Fiber Endoscope Scanner Probe Utilizing Two-Degrees-of-Freedom (2DOF) High-Order Resonance to Realize Larger Scanning Angle

An electromagnetically driven single-fiber scanner that utilizes a two-degrees-of-freedom (DOF) second-order resonance to realize a larger field scanning scale has been proposed and verified by experimental measurement. A 2DOF system structure, including fiber, magnet, and weight, has been designed, which can execute high-order resonance modal to extend the scanning angle in the limited dimensional tube of the endoscope with 2-mm outer diameter. A low-cost, flexible microcoil embedded in polyimide film is also fabricated to drive the fiber-magnet-weight 2DOF system to vibrate. The magnetic field distributions of the microcoil with different structural parameters are simulated. The experimental measurement verifies that the scanner utilizing the second-order resonance mode has successfully realized a 9.47° scanning scale, which is much larger than the 2.98° obtained at the traditional first-order resonance mode. The scanning locus of fiber tip in the fabricated scanner probe has been obtained in the xy plane by standard position sensitive detector (PSD). The developed fiber scanner probe is promising to the ultrathin endoscope used in the narrow space of the human body.