Face electrodes let you taste and chew in virtual reality
Face electrodes let you taste and chew in virtual reality
By Victoria Turk 4 November 2016, updated 4 November 2016
You’re having dinner in a virtual reality game. The
banquet scene in front of you looks so real that your mouth is watering.
Normally, you would be disappointed, but not this time. You approach the food,
stick out your tongue – and taste the flavours on display. You move your jaw to
chew – and feel the food’s texture between your teeth.
Experiments with “virtual food” use electronics to
emulate the taste and feel of the real thing, even when there’s nothing in your
mouth. This tech could add new sensory inputs to virtual reality or augment
real-world dining experiences, especially for people with restricted diets or
health issues that affect their ability to eat.
Several projects have succeeded in tricking us into
tasting things that aren’t there. Nimesha Ranasinghe at the National University
of Singapore has already experimented with a “digital lollipop” to emulate
different tastes, and a spoon embedded with electrodes that amplify the salty,
sour, or bitter flavour of the real food eaten off it. However, his experiments
with electrical stimulation had less success simulating sweetness compared to
the other tastes. But digitising this taste could be particularly useful in,
for example, helping people cut back on sugary food or drinks.
So Ranasinghe and his colleague Ellen Yi-Luen Do started
experimenting with thermal stimulation instead. Their new project, presented at
the 2016 ACM User Interface Software and Technology Symposium (UIST) in Tokyo,
uses changes in temperature to mimic the sensation of sweetness on the tongue.
The user places the tip of their tongue on a square of thermoelectric elements
that are rapidly heated or cooled, hijacking thermally sensitive neurons that
normally contribute to the sensory code for taste.
In an initial trial, it worked for about half of
participants. Some also reported a sensation of spiciness when the device was
warmer (around 35 °C) and a minty taste when it was cooler (18 °C). Ranasinghe
and Do envisage such a system embedded in a glass or mug to make low-sugar
drinks taste sweeter.
Your taste receptors may be open to electrical
manipulation, but food isn’t just about taste – texture is every bit as
important. This week, a team from the University of Tokyo presented a device
that uses electricity to simulate the experience of chewing foods of different
textures. Arinobu Niijima and Takefumi Ogawa‘s Electric Food Texture System
also uses electrodes, but not on the tongue, instead they place them on the
masseter muscle – a muscle in the jaw used for chewing – to give sensations of
hardness or chewiness as a user bites down. “There is no food in the mouth, but
users feel as if they are chewing some food due to haptic feedback by
electrical muscle stimulation,” says Niijima.
To give the “food” a harder texture, they stimulated the
muscle at a higher frequency, whereas a longer electric pulse simulated a more
elastic texture. Niijima says their system was most effective at mimicking the
texture of gummy candy.
Like the flavour work, this technology could also help
modify the texture of real food. At UIST, participants wore the electrodes
while eating cookies. Ranasinghe, who tried the device, says it changed the
cookie’s texture to something harder and chewier – like gummi bears.
Both projects are still in the experimental stage but
share the goal of helping people with special dietary requirements or health
problems. “There are many people who cannot eat food satisfactorily because of
weak jaws, allergies, and diet,” says Niijima. “We wish to help them to satisfy
their appetite and enjoy their daily life.”
He says the team will develop the idea by targeting
additional muscles in the jaw to create more complex textures, and combining
the electrical stimulation with other sensory inputs, such as chewing sounds.
Ranasinghe says that a Singapore hospital is planning a
long-term study with the electrode-enhanced spoons to try to reduce sodium
intake in its elderly patients. Many older people lose their sense of taste and
prefer stronger flavours, but adding too much salt can contribute to health
problems such as high blood pressure. The spoon acts like electronic seasoning
instead.
Put together, all of these technologies could one day be
incorporated into a virtual reality headset to create a multisensory dining
experience.
“I think the main advantage is to increase the immersion
inside the virtual environment,” says Ranasinghe.
He gives an example: an astronaut could put on a headset,
soak in a relaxing view from back home, and have a nice cup of virtual coffee.
Journal reference: Proceedings of the 29th Annual
Symposium on User Interface Software and Technology, DOI:
10.1145/2984751.2985729
Proceedings of the 29th Annual Symposium on User
Interface Software and Technology, DOI: 10.1145/2984751.2984768
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