3D-printed bricks that look like Legos could provide a simple, low-cost way to make sound holograms - 3D shapes and structures made from sound - for a variety of applications, such as entertainment, medicine, or wireless charging, according to a recent study,
Anyone who's seen Star Wars is familiar with the concept of an optical hologram -- a 3D image that floats in mid-air -- even though the technology in real life is far less advanced than what's depicted on the screen.
A hologram is actually a recording of a 3D light field that projects a replica of the original when it is well lit. (The term hologram can refer to both the recording medium and the resulting projection.) The concept of holograms can be applied to sound waves to produce acoustic holograms, although according to the scientists who developed this new method, this area of research is still very new. 10 Future Tech 'Star Trek' Fans Would Love to See
Previous methods have required complex arrays of speakers and control electronics. But now, researchers have demonstrated how sound waves from a single speaker can be bent into complex 3-D shapes using a wall of intricately designed plastic bricks.
is a computer rendering of a sound wave that travels through a series of acoustic metamaterials and is shaped into a pattern, like a letter passing a foot through the array. This pattern cannot be seen, only heard. (Duke University)
"What we've shown is that you can create a very complex sound field from a very simple source using carefully designed and engineered structures," said Steve?
"It's a lot like a holographic film, where you put it in front of a beam of light and what gets sent out is "a much more complex sound field," said Cummer, a professor of electrical and computer engineering at Duke University in North Carolina. It's just an addition to any source you already have, and it's relatively easy to fabricate," he told Live Science.
Building "bricks" Bricks are so-called metamaterials, a family of materials with specially engineered microstructures that lead to unusual properties not found in nature. in essence. The team designed 12 different types of bricks that can effectively slow down sound waves at different rates.The bricks were made with a conventional 3D printer and used as pixels for holograms. An improved optical hologram design algorithm was used to determine the structure of the bricks needed to reproduce the desired 3D sound field.
In a paper published Oct. 14 in the journal Scientific Reports, the researchers describe using this method to make 256-pixel holograms to convert uniform sound to wave sound waves into the sound field in the form of the letter a. The holograms were used to create a hologram of the same shape as the hologram. The scientists made another hologram by focusing the sound energy onto multiple circular dots of different sizes that acted as holographic lenses.
Cummer emphasized that the research is exploratory at this stage. But Yangbo "Abel" Xie, a doctoral student in Cummer's lab and the paper's first author, said the approach has significant advantages over previous methods that relied on speaker arrays.
"Other methods consume a lot of power; they require quite complex control circuits and electronics," Xie told Live Science, and because the system is more complex, it tends to be more unstable. With our method, once you've built the hologram, it lasts a long time, is very stable, and doesn't consume any power.
Hsieh added that one potential application of the technology is audio loudspeakers, and he said the university's commercialization office is actively looking for industrial partners to help develop the technology He said:
"The loudspeaker not only conveys frequency and pitch information, but also provides spatial information." If you play a cello kit on your iPhone, it sounds like a loudspeaker playing a cello kit. One potential application is that we could use holograms to reconstruct a better acoustic scene where you have a more realistic sense of the spatial information of the sound.
An innovative ideaPeer Fischer, a physical chemist at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany, who was not involved in the study, said the new approach looks promising. His team recently produced acoustic holograms from ultrasound waves using specially designed 3D-printed plastic blocks.
"This is particularly promising for long-wave, low-frequency acoustics because it makes the elements of the holograms very compact," he told Live Science of the exciting possibilities their method will open up in terms of forming sound fields.
However, the researchers also hope to tweak their method to manipulate ultrasound. Ultrasound has a much shorter wavelength, so that would mean shrinking the bricks to a hundredth of their current size, Cummer said:
Cummer and his colleagues collaborated with scientists at the Massachusetts Institute of Technology to create an early version of the millimeter-sized bricks with smaller internal features.
The researchers believe this could lead to better ultrasound imaging devices.
Current systems use arrays of transducers - basically, megaphones - to generate precisely controlled sound waves, but the small wands need to be connected to a large machine that houses a complex control system. Systems using this approach could be more compact, says Prof. Xie.
A number of startups are also working on using ultrasound to wirelessly charge cell phones, and Prof. Hsieh said their approach could greatly simplify how these systems are controlled.
It was the original article on life sciences.