Immersion (Canada)

Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick-slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function.

This paper describes the characteristics and benefits of high definition (HD) haptics that aims at improving the user interface in electronic devices. A development platform has been created that combines a high performance piezoelectric actuator, a sophisticated controller, and design tools to deliver a wide range of haptic effects both in magnitude and frequency. Consumer electronics engineers can leverage the development platform to explore the benefits of implementing HD haptics in new electronics devices (e.g. cell phone).

This paper addresses the question of strength perception for vibration signals used in mobile devices. Employing devices similar to standard cell phones and using pulsed vibration signals to combat adaptation effects, experiments were performed to study the effect of weight and underlying on perceived strength. Results shows that for the same measured acceleration on the device, a heavier box is perceived to vibrate with greater strength. Furthermore, signals with higher underlying frequency are perceived to be weaker for the same measured acceleration. While our results are consistent with previous studies, they are obtained for the specific condition of ungrounded, vibrating objects held in the hand. Our results suggest the need for a systematic correction law for use by designers to specify the vibratory characteristics of a device as a function of its weight and of the desired operating frequency.

This paper presents a generic software architecture developed to allow users located at different physical locations to share the same virtual environment and to interact with each other and the environment in a coherent and transparent manner.

ABSTRACT The fact that French immersion programs in Canada have undergone such rapid expansion in the last few years attests to the enormous success and general approbation that the immersion phenomenon has enjoyed. In the rush to put the program in place, however, one necessary factor to ensure its continued success has been overlooked: the training of immersion teachers. In this paper, the authors outline a course designed to prepare primary immersion teachers, and discuss general implications for the training of teachers competent to meet the challenge of immersion programs.