The Effect of Actuation Speed on the Perception Threshold of a Squeezing Soft Actuator

The actuation speed of a pressure stimulus may
influence its perception threshold. This is relevant for the design
of haptic actuators and haptic interaction. We ran a study using
a motorized ribbon to apply pressure stimuli (squeezes) to the
arm at three different actuation speeds and used the PSI method
to find the perception threshold for 21 participants. We found a
significant effect of actuation speed on the perception threshold.
Namely, a lower speed seems to increase the thresholds of normal
force, pressure and indentation. This could be due to multiple
factors like temporal summation, stimulating a larger population
of mechanoreceptors for faster stimuli, and different responses
of SA and RA receptors to stimuli of varying speeds. Our
results show that actuation speed is an important parameter
for the design of new haptic actuators and the design of haptic
interaction for pressure.