Biomedical Engineering Reference
In-Depth Information
7
Tactile Display Technology
A tactile device is a man-machine interface that can reproduce accurately tactile
parameters such as texture, roughness, temperature, and shape, and is used in virtual
environments (VEs) (applications based on virtual reality technology) and teleoperation
applications [1, 2].
This chapter provides an overview as to what has been achieved so far in this field
and to summarize the different specifications that may contribute to the development and
evolution of future tactile interface and display systems.
The following list classifies the domain and possible applications for various tactile
interfaces:
•
teleoperation and telepresence;
•
laboratory prototypes to study different tactile parameters;
•
sensory substitution;
•
3D surface generation;
•
Braille systems;
•
games.
From a technological point-of-view, tactile stimulation can be accomplished in a number
of different ways. Technologies used for VE systems were inspired by dot matrix printers
technologies and Braille systems for the blind. Solutions have been proposed based on
mechanical needles actuated by electromagnetic technologies (solenoids, voice coils),
piezoelectric crystals, shape-memory alloys (SMAs), pneumatic systems, and heat pump
systems based on Peltier modules and dielectric elastomers.
Other technologies that use electrorheological fluid (ERF) are still under investigation.
When subjected to an electrical field, this fluid changes its consistency from thick to thin
within milliseconds, making it useful in many different hydraulic actuator applications.
These, and other technologies shown in Figure 7.1, can be used in the field of tac-
tile sensing to provide information on various sensations, such as vibration, shear, heat,
pressure, friction, scratch, and indentation [3].
