While some companies are developing what most people would call holograms, none have allowed for direct manipulation like the kind seen in sci-fi movies—until now.
Researchers from the Public University of Navarra claim to be the first to have developed holograms, officially known as volumetric displays, that users can directly manipulate with their hands. Possible manipulations include grabbing and dragging virtual 3D objects, similar to tapping and dragging icons on a 2D smartphone screen. This technology could have practical applications in educational settings such as classrooms and museums. The researchers will present their work at the 2025 Conference on Human Factors in Computing Systems, taking place in Yokohama, Japan, from April 26 to May 1. The study describing the breakthrough now appears in HAL.
Traditional volumetric displays use a rapidly oscillating sheet called a diffuser. The display projects images onto the diffuser at different points in its oscillation, but it happens so fast that our eyes see all the projections at once as a complete volume. While this produces reliable 3D graphics, they can’t be manipulated directly.
“The problem,” the researchers explained in a university statement, “is that the diffuser is usually rigid, and if it comes into contact with our hand while oscillating, it may break or cause injury.”
As such, traditional volumetric displays are usually exhibited beneath a safety dome, meaning that viewers can only interact with the 3D graphics in indirect ways. These indirect interactions include using a 3D mouse, pointing into the dome, or using cameras to track hand movements and replicate them with an avatar, as first author Elodie Bouzbib explained in a video.
To overcome the safety hazards of a rigid diffuser, Bouzbib and her colleagues used an elastic one. As detailed in a university video, the novel design consists of multiple elastic strips lined up side by side, allowing users to interact with the 3D graphics by inserting their fingers between the strips as the diffuser oscillates. Because elastic material distorts graphics, the team had to adjust the images in real time.
With this approach, possible manipulations include “grasping a cube between the index finger and thumb to move and rotate it, or simulating walking legs on a surface using the index and ring fingers,” the researchers explained in the statement. If someone tried doing this with a traditional, solid diffuser, they’d probably break a finger.
Furthermore, “having three-dimensional graphics that can be directly manipulated has applications in education—for instance, visualising and assembling the parts of an engine,” the researchers pointed out. “These displays could be particularly useful in museums, for example, where visitors can simply approach and interact with the content.”
In other words, a real-world holodeck, like the one portrayed in Star Trek, might not be so far off.