Game Development Reference
In-Depth Information
In the University of Hull GB, department of electronics, a tactile interface in a
5
5 matrix form based on electrorheological fluid-based actuators has been made
for VE applications (Taylor et al., 1996a; Taylor et al., 1996b). After validation of the
concept for an actuator, a 5
×
×
5 actuator matrix has been developed. Each actuator
11mm 2 with rounded edges with a radius of 1mm. Each actuator can be fed
independently with a voltage of 2.4 kV.
In the Microelectromechanical Systems Laboratory of the Carnegie Mellon Uni-
versity, researchers have developed a matrix tactile interface based on the MEMS
technologies. The MCNC MUMPS chip groups 24 actuators of different sizes on an
area of 1 cm 2 . The dimensions of an actuator are approx. 2
is 11
×
2mm. The central part
represents the place where the polyamide layer reacts and creates a sensation on the
finger. Following these initial works, a collaboration between the Touch Lab of MIT
and MEMS Lab of CMU has been initiated. The works carried out as part of this
collaboration have made it possible to make a unit actuator that is made of two cham-
bers containing a fluid. The two chambers are connected by a common membrane in
such a way that when the exterior membrane is displaced by an electrostatic force, the
internal membrane is displaced by the movement of the fluid with a greater range of
movement.
In Enikov et al. (2002), the authors describe a 4
×
5 vibratory actuator matrix. The
technology used is based on the silicon technologies. Each microactuator is triggered
by a pair of thermal actuators, while the vibration is generated by a piezoelectric blade.
S. Ino from the University of Hokkaido undertook experiments to study the
human ability to identify different materials (aluminium, glass, rubber, polyacrylate
and wood), based on temperature variations 7 of the skin at the level of the fingertip,
by touching the material (Ino et al., 1993). The temperature of the display surface
is measured by a thermocouple and a Peltier effect module that heats and cools. The
temperature interval ranges between
×
60 C with a resolution of 0.1 C.
The researchers of the University of Berkley (Cohn et al., 1992) have developed a
10 C and
+
5
×
5 pressure actuator prototype with a resolution of 3 bits. The pneumatic interface
(5
5 prototype) helps to generate a maximum force amplitude of 0.3N per element,
bandwidth of 8Hz (
×
3 dB), and a force resolution of 3 bits. The present tactile interface
is formed by a single piece of moulded silicon.
Researchers in the Higuchi Lab at the University of Tokyo have developed a tactile
interface based on linear electrostatic actuators. The actuator is made up of a thin
sliding film and a stator. The user can obtain tactile sensations by moving the sliding
film with the finger. The linear electrostatic actuator generates shear stress of the finger
of the user according to the position of the sliding film, which makes it possible for
the user to obtain a few tactile sensations.
In order to demonstrate that the curve perception is mainly a result of the path
of the deformed area of the fingertip during its contact with the explored object,
the Vincent Hayward team at the McGill University developed an interface called
Morpheotron which incorporates a surface with two degrees of freedom of rotation on
which the operator places his finger. In the case of large curves, it is possible tomove this
surface in a horizontal plane of 280
280mm 2 (Dostmohamed & Hayward, 2004).
×
7 More specifically the difference between temperature gradients.
 
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