TastyFloats: A Levitating Food Delivery System

Are you still relying on utensils like forks and spoons to convey food into your mouth? The SCHI Lab at the University of Sussex is here with TastyFloats, a contactless food delivery system that uses ultrasound to levitate, transport, and deliver delicious morsels directly onto your tongue. Want to enjoy food that is scientifically proven* to taste better, while experiencing an innovative gustatory interface and new culinary experiences? Keep reading to find out how!

The magic powering TastyFloats is a well-established trick that we’ve written about extensively—primarily in the context of creating mid-air tactile feedback, but also in object manipulation. Two phased arrays of low-cost ultrasonic transducers opposite each other form a standing wave of ultrasound between them, and very small amounts of liquids and solids can be suspended in the nodes of the wave. Changing the phase can move these nodes in three dimensions, pulling the contents along with it, and allowing the materials to be transported in 3D space as long as they stay between the arrays.

Doing this with food is surprisingly tricky, because food is so variable. The ultrasound will impart heat to whatever it's levitating, causing alcohols to begin to evaporate. High density foods (like cheeses) require more power than low density foods. And the overall system has to be tuned to adapt to foods of different weights to be able to properly control their respective exit trajectories so that they land on just the right spot on your tongue.

The point of this whole exercise is to be able to understand how our perception of food changes if it's reduced to an isolated morsel that can be deposited into your mouth without anything else intervening, which is an unprecedented level of control. The researchers experimented with three of the five basic tastes: sweet (a positive taste), bitter (a negative taste), and umami, which is a savory taste that can also enhance other flavors. The researchers asked a group of volunteers to test TastyFloats with the three basic tastes, delivered in three different volumes (5 microliters, 10µL, and 20µL), with tongue delivery via pipette as a non-levitating control. Participants were asked to identify each droplet, and then rated each on intensity, pleasantness, and satisfaction.

The most significant difference between levitated tastes and tastes delivered via pipette was in intensity: sweet tastes were more intense and recognizable, while bitter tastes were harder to distinguish. The researchers suggest that this might make TastyFloats more suitable for dessert delivery, although it could also be used to make bitter but healthy foods (like broccoli) more palatable to people who wouldn't otherwise enjoy them. 

There are all kinds of ways that TastyFloats (or a system like it) could potentially be used, the researchers say. Most of them sound a little crazy, so I'll let the paper tell you about it:

TastyFloats not only helps to change the way we experience food in the future, but also inspires and provides guidance on how to design novel end-to-end gustatory interfaces. For example, TastyFloats can change the manual approach in Edible Cinema, by integrating an end-to-end food delivery system in the back of a front-seat for the viewers to get time-synchronized food delivery in mid-air. The audience can then decide whether to accept or ignore the proposed gustatory stimulus simply by leaning forward or back whenever they want. Similarly, in a desktop gaming environment, the TastyFloats framework can guide the design of multi-user levitation systems, where different stimuli represent reward or punishment. 

TastyFloats was demonstrated for levitating single food morsels but, as shown in the accompanying video, also provides the foundations to be expanded for multiple morsels. Complex food, such as the ingredients of a burger combining bread, meat, and lettuce can be easily levitated. We can specify and control the path of a set of ingredients and ensure that the food arrives on the customer’s tongue in the chef’s preferred fashion (e.g., first bread then meat). This opens the possibility of making recipes by mixing tastes directly on the tongue of the customer to create surprising experiences.

I'm… Not sure I'm ready for any of that, to be honest, but I'd still be willing to give TastyFloats a try, tongue first.

TastyFloats: A Contactless Food Delivery System, by Chi Thanh Vi, Asier Marzo, Damien Ablart, Gianluca Memoli, Sriram Subramanian, Bruce Drinkwater, and Marianna Obrist from the SCHI Lab at the University of Sussex will be presented later this month at ACM ISS.

*More like, suggested by a study involving 11 volunteers


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