A Force Sensor for Multi-Physics Detections and their Decoupling in Practical Field Applications

Capacitive force sensors were developed by engineering the geometry of electrodes, operating principle, and algorithm in this work. A special electrode and spacer arrangement that allows decoupling of multi-physics was thus realized with four triangular- and one diamond-shape capacitors in the sensing unit. The proposed design avoided multiple structures with fabrication simplicity and practicality. Additionally, the square sensing unit provide expansion potential in an array, supporting various applications. To demonstrate the operation, the sensor was fabricated and evaluated; and the average detection tolerance was confirmed less than 1̊ under a composite force, when both the shear angle and normal angle were involved. The proposed sensor was successfully proved eligible to decouple signals through blind tests (without knowing the applied physical quantity) and a corresponding algorithm for the first time.