Can multiple tactile pressure stimulation in gripping position induce virtual force directions?

Perception of minute force direction through tactile sensations during tool manipulation is an important factor for humans in skill acquisition. Different pressure levels on finger contacts could be responsible factors pertaining to the perception of force direction. In this paper, an experimental study was done to verify if pressure stimulation pattern applied to the thumb and fingers on a gripping position could produce a sense of force direction. Six participants performed a force direction discrimination experiment by holding a grounded pen type interface which induces pressure sensation using air suction technique. Experimental results showed that participants felt three distinct force directions from applied pressure stimulation patterns. It was verified in this experiment that the feasibility of applying different pressure levels at skin contact locations on a pen grip position can produce a sensation of force directions.