Design and fabrication of driving microcoil with large tilt-angle for medical scanner application

This paper presents an electromagnetically-actuated single optical fiber scanner that utilizes its high-order resonance modal and tilt microcoil to realize a larger scanning angle. The device is fabricated on the surface of a thin polymer tube with 1mm diameter by our developed spray coating and cylindrical projection lithography systems, which could be used as ultra-thin medical endoscope. In order to realize the electromagnetically-driven scanning, a cylindrical magnet is fixed at the center of the polyimide pipe by an optical fiber. When an AC power is supplied to the microcoil, the fiber scanner is actuated under a certain frequency. The modal and dynamic response of the designed scanner under high-order vibration has been simulated and analyzed. The microcoil with 60° tilt angle is fabricated by wet etching and maskless electroplating processes. The electromagnetic property and maximum driven displacement of the fabricated device have been also evaluated, which is generally in accordance with that simulated. Finally, the electroplated microcoil of 60° tilt-angle, 40μm line width, 40μm line spacing and 15μm thickness has been obtained successfully.