Fingertip Pressure Feedback Increases the Perceived Length of a Handheld Object

In haptics, supporting dynamic touch, the perception of object properties such as length and shape through wielding, remains a significant challenge, often requiring complex and bulky devices. This paper investigates whether the perceived length of a wielded physical object can be augmented using only dynamic cutaneous (pressure) feedback to the fingertips, motivated by the recent advancement of haptic gloves. We designed pressure feedback profiles inspired by the biomechanical changes in finger pressure that naturally occur during wielding. These profiles deliver sequential pressure stimuli to the fingertips, synchronized with the object's rotational angle during wielding. A perceptual experiment demonstrated that the fingertip pressure feedback significantly increased the perceived length of an elongated object by 6.1% on average. This effect was equivalent to an increase of 13.8% in the physical moment of inertia of the object. This finding suggests that cutaneous feedback can effectively modulate the perceptual properties of handheld objects mediated through dynamic touch, expanding the application areas of hand-worn haptic devices.