Remember the scene in Iron Man 2 where Tony Stark rediscovers a new element and is handling virtual 3D holographic elements with his hands, moving them around, pinching, swiping, flicking, and tossing? Pretty cool in 2010. What about 2025?
Well, we're not quite there yet, but this is still pretty innovative: A team of Spanish engineers has created the world's first 3D hologram that can be physically interacted with.
Holograms are generally made using swept volumetric displays, meaning images are projected at different heights nearly three thousand times per second onto a rigid oscillating surface called a diffuser, giving the appearance of a three-dimensional object without the need for special glasses or headsets. The diffuser moves so fast that it's mostly imperceptible to the human eye. The catch is, that the second you try to interact with the hologram, you might lose a finger or just break the machine entirely.
Doctor Elodie Bouzbib, of the Public University of Navarra, and her team developed a simple solution: elastic diffuser strips.
While it might sound easy, the team tested many iterations, materials and types of strips, from projector screen material to silicone. Not just for elasticity and hysteresis (maintaining its original shape after being stretched), but also for its optical properties. "Elastic bands" are what they chose as the most suitable material to create their system called FlexiVol, but did not specify exactly what kind of "elastic band."
Using gestures you're already accustomed to with your phone's touch screen – swipe, touch-to-select, pinch, rotate and more – a user can effectively control and manipulate these holographic objects through the elastic diffuser.
The standard method of interacting with a hologram or other 3D space is a 3D mouse, which looks more like something you'd find in Mission Control than an everyday mouse. Extremely precise, but not especially fast without practice.
To validate the concept, the team performed three use-tests, with 18 participants pitting a 3D mouse against FlexiVol; selecting an object, tracing an object, and docking – where the user had to place an object within an object.
In the selection test, users were significantly faster at poking the ball (selecting) with their fingers than with the 3D mouse. Tracing, interestingly enough, was roughly the same speed, but when overlapping trace routes between the two methods and comparing them, FlexiVol subjects were far more accurate in their traces. The docking test, as one might imagine, FlexiVol won by a landslide with its much more intuitive grab-with-your-fingers-and-chuck-it-in approach.
Though the test subject sample was relatively small at only 18, 94% of users said they were more confident in their completion times and 67% more confident in accuracy compared to using the 3D mouse. The reach-through method felt more accurate, more natural, and less frustrating than the mouse, they said.
Dr. Bouzbib has said she's looking to further improve the design using focused ultrasound or conductive threads to simulate haptic feedback ... leaving me wondering if the flappy elastic isn't shocking enough.
Source: Public University of Navarra
