Hi everyone! My name is Anandghan and I’m a PhD student at the University of Washington.
Today, I’m very excited to tell you about our project UbiquiTouch!
UbiquiTouch is a new way to create touch interfaces which are wireless, self-sustaining and which could
be deployed over everyday surfaces.
And such UbiquiTouch interfaces can be used in a variety of situations.
Using conductive threads, UbiquiTouch can add touch interaction to clothing and can
be used in on-the-go scenarios.
UbiquiTouch can also add touch interaction to paper. Here, swiping on an event sends
the event details to the user's phone.
UbiquiTouch interfaces can be deployed without any special setup in the environment
such as Here, a poster is used to gather people's votes among the given choices.
UbiquiTouch can also add interactivity to books
In this example, a letterboard is made interactive using UbiquiTouch.
UbiquiTouch operates using a custom low power circuit which detects touch and encodes the
touch location to be sent over wirelessly.
This circuit is entirely powered by energy harvested from ambient light using a photovoltaic
cell
To save on power UbiquiTouch communicates using the technique of backscatter communication
Backscatter communication helps to save power by modulating and reflecting existing RF radiation.
This eliminates the power intensive operation to self generate high-frequency RF signals.
In the event of a touch, UbiquiTouch can transmit the touched location to nearby smartphones
with built in FM radio.
The detected location on the touchpad is encoded as a binary data packet and transmitted by
backscattering ambient FM radio waves.
This transmission is received as an audio signal by the smartphone which is then processed
to identify and decode the data packets.
By repurposing widely accessible radio waves from FM radio stations and receiving them
on existing smartphone with users, UbiquiTouch can be deployed without requiring
any special setup such as RFID readers in the environment.
To evaluate the system, we ran a study to assess the accuracy, the power consumption of
the system and the response time of the system
For the accuracy evaluation, we performed the study in multiple real life scenarios.
For one setting we asked the user to hold the phone in their hand and in the other setting
to keep phone in pocket.
And we repeated both these setting in both outdoor and indoor scenarios.
From the study results, we found that the system performance was consistently high across
all the different scenarios
The average power consumed by the system was about 31 uW and from this result we can conclude
that UbiquiTouch can run both indoor and outdoor in regular lighting conditions
The response time of the system was about 0.7 seconds. Majority of which was the time
required to forward data from the phone to a laptop for processing. This time can be
avoided if the processing is directly done on the phone.
Without this extra time, the response time of the system was about 0.4 seconds.
To provide a good user experience with this system performance, we made the user interactions
longer by stretching a single touch point into longer shapes as shown in these examples.
This helped to mask the latency and provide a good user experience.
In conclusion, we built a wireless touch interface platform which works with out batteries
and does not require any specially modified environment for operation.
If you found this work exciting, lets have a chat!
Thank you so much for your time!