Hello everyone.
I'm Aditya Nittala, assistant professor in the Department of Computer Science
at the University of Calgary.
On behalf of my students, Peter, Purna and our co-author Jay Lee from UNIST, I'm
presenting our work on augmenting on on-body touch input with tactile
feedback through fingernail haptics.
The human body offers a large and really accessible surfaces for always
available eyes free interaction.
For these reasons, sensing, touch input, put on the body has received considerable
attention in the HCI community.
However, the key assumption attributed to On-body touch input is that the skin that
is being touched provides natural tactile feedback when interacting with the body.
This is analogous to mobile devices during their infancy.
There was touch screen, but no haptic feedback.
Then several research works showed that coupling tactile feedback with touch input
can create highly expressive interactions.
That is very much evident from our daily interaction with mobile devices.
For instance, when we perform a text-entry task, we get subtle tactile feedback to
indicate that a key has been pressed.
. Similarly tactile feedback has also been shown to be very effective
for enhancing touch interactions in automotive interfaces too.
In line with this theme, we propose the haptic augmentation of on skin
interfaces, where our aim is to augment on body touch input with tactile feedback.
Instead of the natural tactile feedback, augmenting on-body touch input with
computer generated tactile feedback can produce highly expressive interactions.
And how can we do this?
There are multiple approaches for augmenting on-body touch
input with tactile feedback.
The brute force, or the most rudimentary approach, is to place an actuator on the fingered.
However, this will diminish our natural tactile sensing capabilities.
The second approach is to augment the fingertip with thin film
electro tactile interfaces.
For instance, a device such as TACTOO , which is published in UIST 2018.
The drawback of this approach is that these devices have very limited
mechanical robustness and can be destroyed over the course of numerous
daily activities that our fingers perform.
The third approach is to augment the skin with thin film electro tactile interfaces.
However, this approach is not scalable and requires placing.
The devices at every location on the body Where touch input needs to be performed.
Instead of these approaches, we use fingernails for providing tactile
feedback by placing an actuator.
There are several advantages for this approach.
Firstly, it keeps a fingerpad unencumbered.
Secondly, it's highly scalable.
A single actuator is sufficient for rendering, tactile click sensation for touch
buttons pressed anywhere on the body.
Finally, it has been used extensively, And prior research has also
shown that fingernails can be good locations for rendering highly
articulated spatio-temporal patterns.
This is a snippet showing how the actuator vibrates in response to a touch.
to provide tactile feedback.
Taking this as our base, we conducted three psychophysical experiments
to understand the haptic augmentation of once interfaces.
Our first research question was, do users prefer tactile feedback
for interaction on the skin?
In the second study, we were interested in identifying the vibration intensity
thresholds for rendering suitable tactile click sensations for on-body touch input.
Finally, in the third study, we show that computer generated tactile
feedback can enhance the exclusivity of on-body touch buttons.
In the first study, we were interested to see if participants preferred augmenting
tactile feedback for on-body touch buttons.
For this, we fabricated a capacitive touch sensor, and coupled the touch
input to tactile feedback through actuation on the fingernail.
We performed this study under two interaction conditions.
The first one is eyes free condition, where there was no visual feedback of touch input.
participants were by blindfolded before performing touch input.
The second feedback was a visual feedback condition where a
virtual button press was presented on a computer screen.
We use the first condition to be in line with situations where on-body
touch input can be used for on the go Eyes-free interaction, and the second
condition to be in line with situations where on-body input is mapped to an off-body display.
and as you can see, Our overall results
show that participants prefer tactile feedback in all the conditions.
In addition to the likert scale readings, participants also provided valuable
insights with regards to tactile feedback.
Firstly, we fired the actuator at default intensity, and this was
Too strong for on-body touch input.
Secondly, participants also suggested that different tactile patterns can be.
Used for producing variations in tactile feedback, and all the participants
did highlight the importance of tactile feedback when they were
performing touch input on the body.
In the second study, we were interested in understanding the thresholds for
Rendering natural tactile click sensations.
This is, again, coming in from the results of the first study where
participants felt that intensity of the vibrations was too.
In this study, we performed the experiment on three body locations
because our body has varying levels of mechanoreceptor concentrations. We
counterbalanced the order of presentation for body locations and used the method
of limits, to determine the thresholds.
We use pulse width modulation to control the
vibration intensity of actuator.
Results show that body locations do influence the thresholds.
However, it is also interesting to note that the differences are not very drastic.
In our third experiment, we wanted to understand the human capability of
differentiating diverse tactile effects with a single actuator on the fingernail.
For this study, we chose 20 different tactile effects that are suitable
for on body touch buttons.
We chose this rich tactile haptic effects from the Touchsense library,
which has been extensively used in literature for creating rich tactile effects.
To the best of our knowledge, we are the first to employ non-metric,
multi-dimensional scaling, a classical psychophysics methodology in the
context of on-body interfaces.
For the procedure, we had a control software where participants
clustered the different effects based on their similarity.
Each cluster had a bin and participant had to group the effects in those
bins based on how similar they were.
After this, we performed multidimensional scaling to see
the similarity or dissimilarity between those effects.
It is interesting to note the baseline condition, which is on the right
end of the spectrum, suggesting that there is always a distinct difference
in perception on augmenting tactile feedback.
Secondly, it's also interesting to see that there is a family of soft
tactile effects, and this was deemed suitable for providing subtle tactile
feedback for text entry on the body.
Overall, we show that actuation on the fingernail is a very
promising approach for enhancing the Expressivity of on-body interaction.
There are a few limitations of our work.
Firstly, we focused our studies on taps, which is most primitive touch interaction.
Other widgets interaction techniques such as sliders, pressure based input
need to be studied very thoroughly.
Secondly, we use a vitrotactile ERM actuator, which is the most common and
simple way for rendering tactile feedback.
Other tactile feedback techniques such as electro tactile actuation also
need to be explored and evaluated to see how they fit in for haptic
augmentation of on-body interfaces.
Finally, We used capacitive sensing approach in in this work.
However, this technique of haptic augmentation can scale to
other sensing techniques that allow for touch interaction on the body.
To summarize with proposed haptic augmentation of onscreen interfaces
to increase the exclusivity of onboard interaction, this work presents the
first step in this direction and can be expanded diverse input
techniques on the body, and is also scalable to diverse sensing technologies.
Thank you and now.
I'm open to questions.