Initial design and analysis of a capacitive sensor for shear and normal force measurement

Initial experiments characterizing a shunt-mode sensor that simultaneously measures both normal and shear strains due to an applied force vector have been completed. The sensor, termed SCCINS (sensed capacitance changes due to incident normal and shear stress), is based on variations in the physical dimensions of an elastic dielectric due to applied forces. Two sinusoids of the same frequency but with a fixed phase relationship are used to excite the device. The amplitude and phase of the output signal are modulated by normal and shear strains, respectively. By measuring the amplitude and phase of the output signal, these strains may be determined, and subsequently used to reconstruct the normal and shear components of the force vector