TacTiles: Dual-Mode Low-Power Electromagnetic Actuators for Rendering Continuous Contact and Spatial Haptic Patterns in VR

Abstract

Figure 1: TacTiles are small and light form factor tactile elements that can be placed anywhere on the hand to render contact with virtual objects and enable haptic surface exploration. An individual TacTile is able to produce 200 mN of holding force on the finger without any power draw and is dampened on one side to minimize release vibrations.

Capacitive Sensing for Improving Contact Rendering With Tangible Objects in VR

“…Several works focused on the transition between making and breaking contact [17], [18], [19], [20], [21]. For example, Vechec et al [19] opted for a wearable haptic device made of several actuators which can be controlled to engage or disengage a pin against the user's skin, at high rate, using electromagnetic actuators. For example, Kuchenbecker et al [20] endowed a grounded haptic device with a passive cutaneous end-effector.…”

Hedgehog: Handheld Spherical Pin Array based on a Central Electromagnetic Actuator

“…For example, one participant reported that they perceived the slower patterns as smooth circles, while the faster ones seemed more "random". The exhibited JND allows for several levels of speed rendering, and its possible that other patterns may exhibit different levels of sensitivity [10].…”

“…Pin array haptic interfaces offer a way to increase the fidelity and localization of haptic feedback on the user's hand. They come in the form of touchable surfaces [5]- [8], wearables [9], [10], and embedded in handheld platforms [11]- [14]. It is desirable to provide varying levels of force intensity as it allows for a larger dynamic range when rendering tactile stimuli.…”

“…In such a configuration, the pins are simple passive magnetic elements leveraging the three degreesof-freedom afforded by the central electromagnet [15]. This allows us to adjust the pin force in a particular activated region dynamically and enables the rendering of various haptic patterns on the device's surface [10], [11]. By using a single actuator with passive actuated elements, we can construct an interface with high pin-density, able to continuously control the force over an affected area, while significantly simplifying the manufacturing and operation of our device 1 All authors are with the Department of Computer Science of ETH Zürich, Switzerland.…”

A Wearable Soft Tactile Actuator With High Output Force for Fingertip Interaction

“…Thus, the concept of wearable devices has been proposed, and tactile feedback has been implemented in wearable devices to transfer information through a new medium, i.e., the skin. So far, various wearable tactile devices have been proposed using piezoelectric actuators, cylindrical motors, servo motors, electromagnetic actuators, pneumatic or hydraulic actuators, and shape memory alloy actuators [6][7][8][9][10][11][12][13][14]. Nonetheless, to create a light-weight, flexible, and high output force tactile device especially for use in a wearable interfaces, more research needs to be done on other soft actuators.…”