  In this research, modeling and analysis of a beam-type touchscreen interface
with multiple actuators is considered. As thin beams, a mechanical model of a
touch screen system is developed with embedded electrostatic actuators at
different spatial locations. This discrete finite element-based model is
developed to compute the analytical and numerical vibrotactile response due to
multiple actuators excited with varying frequency and amplitude. The model is
tested with spring-damper boundary conditions incorporating sinusoidal
excitations in the human haptic range. An analytical solution is proposed to
obtain the vibrotactile response of the touch surface for different frequencies
of excitations, the number of actuators, actuator stiffness, and actuator
positions. The effect of the mechanical properties of the touch surface on
vibrotactile feedback provided to the user feedback is explored. Investigation
of optimal location and number of actuators for a desired localized response,
such as the magnitude of acceleration and variation in acceleration response
for a desired zone on the interface, is carried out. It has been shown that a
wide variety of localizable vibrotactile feedback can be generated on the touch
surface using different frequencies of excitations, different actuator
stiffness, number of actuators, and actuator positions. Having a mechanical
model will facilitate simulation studies capable of incorporating more testing
scenarios that may not be feasible to physically test.
