Floating visual displays created using acoustically levitated particles could lead to galleries of singing heads, and advances in contactless manufacturing.
Most of you must’ve watched Star Wars or The Avengers, and in these movies have seen R2D2 or Iron Man project 3D messages. With the help of some speakers and polystyrene balls, fiction is becoming real at the University of Bristol, UK.
A researcher walks inside a windowless box that looks like a shipping container. This huge box is known as a Faraday’s cage, which is normally used to block electromagnetic fields; however, here it is being used to knock polystyrene balls out of the air. After switching on his laptop, he picks up a tiny polystyrene ball, places it between an array of loud-speakers that can be found at any electronic store, and lets it go. And the ball just stays there, hovering, suspended in mid-air.
This phenomenon is known as ‘acoustic levitation’ – essentially using sound to lift objects by counteracting the force of gravity with the pressure of acoustic waves. In 2015 a collaboration between the two groups unveiled a device known as a sonic tractor beam that could levitate objects and rotate and move them in multiple directions. In the past, such levitating phenomena required speakers to be placed all around the particle, but here, only 64 loud-speakers with a frequency of 40 kHz will do.
The grid of speakers produced acoustic shapes out of high-pressure ultrasound waves that could surround and trap objects in mid-air and be adjusted to rotate and move them. They could levitate polystyrene balls of diameters ranging from 0.5 to 3 mm. They work by bending a beam of sound around an obstacle, and levitate and manipulate an object on the other side. It can be used to manipulate up to 25 balls at the same time!
However, these balls could not represent pixels and create a hologram, because the quality was too poor. They then came up with a different idea: instead of manipulating multiple balls at the same time, they could levitate one ball at high speeds, so that at each instance captured by the human eye, there is an illusion of an image. This works on the concept of persistence of vision.
Back in the Faraday cage, the researcher does this exact thing. He presses something on his computer, and boom! A polystyrene ball moves at VERY high speeds and creates multi-coloured images (because of surrounding lights) that are a few centimetres big! Its speed is about 5Hz, which means it completes five complete rounds of the ‘image’ in one second!
In the last year, developments made at the University of Sussex have progressed in such a way that this phenomenon creates holograms that are used in museums, manufacturing industries, and soon, entertainment!
We take a step towards removing the ‘fiction’ from ‘science fiction’, everyday!
Floating visual displays created using acoustically levitated particles could lead to galleries of singing heads, and advances in contactless manufacturing.
Most of you must’ve watched Star Wars or The Avengers, and in these movies have seen R2D2 or Iron Man project 3D messages. With the help of some speakers and polystyrene balls, fiction has become real at the University of Bristol, UK.
A researcher walks inside a windowless box that looks like a shipping container. This huge box is known as a Faraday’s cage, which is normally used to block electromagnetic fields. However, it is being used here to knock polystyrene balls out of the air. After switching on his laptop, he picks up a tiny polystyrene ball, places it between an array of loudspeakers that can be found at any electronic store, and lets it go. And the ball just stays there, hovering, suspended in mid-air.
This phenomenon is known as ‘acoustic levitation’ – essentially using sound to lift objects by counteracting the force of gravity with the pressure of acoustic waves. In 2015 a collaboration between two groups unveiled a device known as a sonic tractor beam that could levitate objects and rotate and move them in multiple directions. In the past, such levitating phenomena required speakers to be placed all around the particle, but here, only 64 loud-speakers with a frequency of 40 kHz works.
The grid of speakers produced acoustic shapes out of high-pressure ultrasound waves that could surround and trap objects in mid-air and be adjusted to rotate and move them. They could levitate polystyrene balls of diameters ranging from 0.5 to 3 mm. They work by bending a beam of sound around an obstacle and levitate and manipulate an object on the other side. It can be used to manipulate up to 25 balls at the same time!
However, these balls could not represent pixels and create a hologram, because the quality was too poor. So, they came up with a different idea: instead of manipulating multiple balls at the same time, they could levitate one ball at high speeds; so that at each instance captured by the human eye, there is an illusion of an image. This works on the concept of persistence of vision.
Back in the Faraday cage, the researcher does this exact thing. He presses something on his computer, and boom! A polystyrene ball moves at VERY high speeds and creates multi-coloured images (because of surrounding lights) that are a few centimetres big. Its speed is about 5Hz, which means it completes five complete rounds of the ‘image’ in one second!
In the last year, developments made at the University of Sussex have progressed in such a way that this phenomenon creates holograms that are used in museums, manufacturing industries, and soon, entertainment.
We take a step towards removing the ‘fiction’ from ‘science fiction’, every day!
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