A Magnetically Transduced Whisker for Angular Displacement and Moment Sensing

This work presents the design, modeling, and fabrication of a whisker-like sensor capable of measuring the whisker's angular displacement as well as the applied moments at the base of the whisker. The sensor takes advantage of readily accessible and low-cost 3D magnetic sensors to transduce whisker deflections, and a planar serpentine spring structure at the whisker base is used to provide a mechanical suspension for the whisker to rotate. The sensor prototype was characterized, calibrated, and compared with analytical models of the spring system and the magnetic field. The prototype showed a moment sensing range of 1.1N·mm when deflected up to 19.7°. The sensitivity of the sensor was 0.38°/LSB for the angular displacement sensing, and 0.021 Nmm/LSB for the moment sensing. A fully integrated system is demonstrated to display real-time information from the whisker on a graphical interface.