Understanding Continuous and Pleasant Linear Sensations on the Forearm From a Sequential Discrete Lateral Skin-Slip Haptic Device

Abstract

A continuous stroking sensation on the skin can convey messages or emotion cues. We seek to induce this sensation using a combination of illusory motion and lateral stroking via a haptic device. Our system provides discrete lateral skin-slip on the forearm with rotating tactors, which independently provide lateral skin-slip in a timed sequence. We vary the sensation by changing the angular velocity and delay between adjacent tactors, such that the apparent speed of the perceived stroke ranges from 2.5 to 48.2 cm/s. We investigated which actuation parameters create the most pleasant and continuous sensations through a user study with 16 participants. On average, the sensations were rated by participants as both continuous and pleasant. The most continuous and pleasant sensations were created by apparent speeds of 7.7 and 5.1 cm/s, respectively. We also investigated the effect of spacing between contact points on the pleasantness and continuity of the stroking sensation, and found that the users experience a pleasant and continuous linear sensation even when the space between contact points is relatively large (40 mm). Understanding how sequential discrete lateral skin-slip creates continuous linear sensations can influence the design and control of future wearable haptic devices. Index Terms-haptic display, wearable devices, skin-slip feedback, haptic illusion ! C. M. Nunez, S. R. Williams, and A. M. Okamura are with the

HaptoMapping: Visuo-Haptic Augmented Reality by Embedding User-Imperceptible Tactile Display Control Signals in a Projected Image

“…Through a user study, they found that users' sensations of continuity and pleasantness for the stroke stimuli could be maximized by increasing the driving duration and shortening the delay of each voice coil. Nunez et al [15] developed a device that uses rotating motors to present a sequential discrete lateral skin-slip sensation on the forearm. Through a user study, they found that their device can maintain continuity and pleasantness even at a large contact distance.…”

“…Apparent tactile motion [52] is a tactile illusion in which a sequentially activated series of actuators makes a user believe that one actuator is moving along the skin. Although previous studies have applied this illusion to social haptic devices to reproduce a stroking sensation, they have displayed haptic information without synchronized visual information [14], [15], [16], [53], [54], [55]. Our arm-mounted device, however, is capable of the visuo-haptic presentation of stroking sensations by embedding activation signals in a hand image projected onto the user's forearm.…”

“…We conducted another user study using the arm-mounted device to investigate the optimal parameters for maximizing the continuity and pleasantness of the presented stroking sensations. The parameters in this study were the stroking speed and the contact spacing, which affect the continuity and pleasantness of the stroking sensations [14], [15], [16]. We also investigated the effect of synchronized visual information by changing the visibility of the projected hand during the experiment.…”

“…Therefore, there has not been a VHAR system for texture presentation that enables high spatiotemporal consistency and independent visual and haptic designs. As for haptic devices for social touch, conventional systems have focused only on presenting tactile sensation [14], [15], [16]. Therefore, there has not been a VHAR system for social touch.…”

Impressions of Vibrotactile Signals in Older Adults With and Without History of Stroke

“…al. evaluated affective response using rotating tactors and found speed and delay were factors in pleasantness ratings [Nunez et al 2019]. Further, Knibbe et.…”