Simultaneous measurement of bending angle and direction with magnetic cilia tactile sensors

Abstract This work develops and experimentally validates a multiphysics simulation model for magnetic cilia tactile sensors based on tunnel magnetoresistive (TMR) thin films. The model predicts the sensor output as a function of cilium geometry, in particular its width and height, by coupling finite element analysis of cilium deformation with a magnetic field and TMR response model. The deformation model is calibrated using tensile tests of NdFeB/PDMS composites and validated against measurements from a physical magnetic cilia sensor module, with simulated signals showing very good agreement with experiments and yielding a composite remanent magnetization of 50.4 emu ⋅ cm −3 consistent with direct characterization. The framework is then used to perform a parametric study of different cilium geometries and to design an advanced magnetic cilia sensor capable of simultaneously measuring bending angle and direction. Experiments on force, surface roughness and micro-step detection demonstrate that the optimized sensor can detect small forces and fine textures relevant to robotic manipulation and biomedical probing, while the model provides a practical tool for tailoring future magnetic tactile sensors to specific applications before fabrication.