PhDTouch is one of the less exploited sensory channels in human machine
interactions. While the introduction of the tactile feedback would improve the
user experience in several fields, such as training for medical operators,
teleoperation, computer aided design and 3D model exploration, no interfaces
able to mimic accurately and realistically the tactile feeling produced by the
contact with a real soft object are currently available. Devices able to simulate
the contact with soft bodies, such as the human organs, might improve the
experience.
The existing commercially available tactile displays consist of complex
mechanisms that limit their portability. Moreover, no devices are able to provide
tactile stimuli via a soft interface that can also modulate the contact area with the
finger pad, which is required to realistically mimic the contact with soft bodies,
as needed for example in systems aimed at simulating interactions with virtual
biological tissues or in robot-assisted minimally invasive surgery.
The aim of this thesis is to develop such a wearable tactile display based on the
dielectric elastomer actuators (DEAs). DEAs are a class of materials that respond
to an electric field producing a deformation.
In particular, in this thesis, the tactile element consists of a so-called
hydrostatically coupled dielectric elastomer actuator (HC-DEAs). HC-DEAs rely
on an incompressible fluid that hydrostatically couples a DEA-based active part
to a passive part interfaced to the user.
The display was also tested within a closed-loop configuration consisting of a
hand tracking system and a custom made virtual environment. This proof of
concept system allowed for a validation of the abilities of the display.
Mechanical and psychophysical tests were performed in order to assess the
ability of the system to provide tactile stimuli that can be distinguished by the
users.
Also, the miniaturisation of the HC-DEA was investigated for applications in
refreshable Braille displays or arrays of tactile elements for tactile maps
