摘要
•An optimized dielectric design through full-factorial experiment was conducted.•Adjustable desirability function for variety was developed.•Evaluations on dimension, geometry and arrangement were performed.•Successful demonstrations of refence and optimized samples.
Sensitivity maximization for capacitive force sensors by engineering the structural rigidity through three factors − dimension (with four levels), geometry (with three levels), and arrangement (with five levels) of spacers − was studied in this work. The full-factorial experiment method was conducted and the desirability function was utilized for optimizations of normal force sensitivity, shear force sensitivity, and shear angle detection tolerance. Theoretical calculation, numerical evaluation, sensor fabrication, and result analysis were comprehensively performed in this work. Experimental results indicated that the highest normal force sensitivity reached 105.342 pF/N, showing a 7674 % enhancement from the refence (spacers arranged at center, corners, and edges of a sensing unit with 500 μm side lengths in square shapes). Furthermore, a design that considered the trade-offs between sensitivities and shear angle detection accuracy was realized with the normal force sensitivity and shear force sensitivity of 23.362 pF/N (improved by 1624 %) and 0.712 pF/N (improved by 1100 %), respectively; and shear angle detection tolerance on average less than 4.1°.