Halbach-Array Magnetic Coil Arrangement on CMOS Chip for Sensitivity Enhancement of Inductive Tactile Sensor

This study exploits the concept of Halbach array magnets and also leverage the multiple metal layers in the standard CMOS process to design and implement magnetic-coil distributions on the CMOS chip to concentrate and enhance magnetic fields. In this study, four vertical magnetic coils are designed to surround the four edges of traditional horizontal magnetic coil to reduce the magnetic flux loss. Thus, the sensitivity of inductive tactile force sensor (CMOS chip with magnetic bump and polymer filler is improved. Measurements indicate the proposed Halbach array coil design could enhance the sensitivity of tactile force sensor for more than 2-fold, as compare with the one with planar spiral coil.