Abstract
This paper presents a newly designed MR-compatible optical force sensor: its principle, structure and performance. Our force sensor employs an optical micrometry based on differential measure of light intensity. This technology enables highly accurate and sensitive two degrees-of-freedom displacement sensing by using a point source, a photo detector and an optical lens. The developed force sensor achieves MR compatibility by placing all the electric and metallic components outside the scanner room, and extending the light path between the optical components using multi-core optical fibers. The sensor head component is made of glass fiber reinforced poly-ether-ether-keton that helps reducing hysteresis characteristics of plastic resin. The accuracy of this force sensor is better than 1.6 % under the applied force ranging from 0 to 3 N.
