Sound waves to move objects

Researchers recently created an acoustic hologram, or a 3D sound field projected onto a 2D space, which can be used as acoustic tweezers, cages and twisters that manipulate objects as they levitate in air.It may seem straight out of "Star Trek," but it's real: Scientists have created a sonic "tractor beam" that can pull, push and pirouette objects that levitate in thin air.The sonic tractor beam relies on a precisely timed sequence of sound waves that create a region of low pressure that traps tiny objects that can then be manipulated solely by sound waves, the scientists said in a new study.Though the new demonstration was just a proof of concept, the same technique could be adapted to remotely manipulate cells inside the human body or target the release of medicine locked in acoustically activated drug capsules, said study co-author Bruce Drinkwater, a mechanical engineer at the University of Bristol in the United Kingdom. [Watch the Tractor Beam Levitate Objects]Levitating objectsIn the past, scientists have used everything from laser beams to superconducting magnetic fields to levitate objects. And in 2014, researchers at the University of Dundee in Scotland showed that acoustic holograms that act like a tractor beam could theoretically suck in objects."They really just showed the force was there; they weren't able to grab or pull anything," Drinkwater said.The principle behind the new system is simple: Sound waves, which are waves of high and low pressure that travel through a medium such as air, produce force."We've all experienced the force of sound — if you go to a rock concert, not only do you hear it, but you can sometimes feel your innards being moved," Drinkwater told Live Science. "It's a question of harnessing that force."By tightly orchestrating the release of these sound waves, it should be possible to create a region with low pressure that effectively counteracts gravity, trapping an object in midair. If the object tries to move left, right, up or down, higher-pressure zones around the object nudge it back into its low-pressure, quiet zone.But figuring out the exact pattern of sound waves to create this tractor force is difficult, scientists say; the mathematical equations governing its behavior can't be solved with a pen and paper.Reverse-engineered force fieldSo Drinkwater, his Ph.D. student Asier Marzo and other colleagues ran computer simulations through myriad different patterns of sound waves to find the ones that produced the signature combination

Imagine trying to have a conversation with someone in a crowded, noisy room. The high-frequency sound waves from your voice are quickly absorbed or deflected by the surrounding people and objects, making it difficult for the other person to hear you clearly. In contrast, subsonic sound waves would be even more severely limited in their range and penetration, making them even harder to detect or communicate with.Applications of Subsonic TechnologySubsonic technology has numerous applications across various industries, from military and defense to scientific research and environmental monitoring. The unique properties of subsonic sound waves make them ideal for specific uses that require low-frequency sound propagation.Sonar and Underwater DetectionSonar technology relies heavily on subsonic sound waves to detect and navigate underwater objects. By emitting low-frequency sound waves, sonar systems can penetrate deep into the ocean, bouncing off objects and returning to the receiver. This allows submarines, ships, and oceanographers to map seafloors, detect marine life, and track underwater vehicles. The subsonic nature of these sound waves enables them to travel longer distances without significant attenuation, making them perfect for underwater exploration.Imagine being in a dark room, trying to find a friend by shouting their name. The sound of your voice would bounce off walls and objects, helping you locate them. Sonar technology works similarly, using subsonic sound waves to “shout” into the ocean and listen for the echoes to pinpoint underwater objects.Infrasound Monitoring and ResearchInfrasound monitoring and research involve the detection and analysis of low-frequency sound waves generated by natural and

Not limited to moving spherical objects along a path but can also control rotations and move complex floaters like an origami lotus.The experimental setup, with speakers and microphones at either end of a water tank, and vertical scattering objects at the center. Credit: EPFL/LWE CC-BY-SA 4.0After successfully guiding a ping-pong ball, scientists conducted further experiments using both stationary and moving obstacles to introduce complexity to the system. Maneuvering the ball around these objects showcased the effectiveness of wave momentum shaping in dynamic, uncontrolled environments, such as the human body. Fleury emphasizes that sound represents a highly promising tool for biomedical applications due to its noninvasive and harmless nature.“Some drug delivery methods already use soundwaves to release encapsulated drugs, so this technique is especially attractive for pushing a drug directly toward tumor cells, for example,” Fleury says.The potential applications of this method are truly groundbreaking, particularly in the fields of biological analysis and tissue engineering. Using sound waves to manipulate cells instead of physically touching them significantly reduces the risk of damage or contamination. Additionally, the possibility of using this method with light in the future opens up even more exciting opportunities.The researchers’ next aim is to transition their sound-based experiments from the macro- to micro-scale. With SNSF funding secured, they are poised to conduct experiments under a microscope, leveraging ultrasonic waves to precisely manipulate cells at a microscopic level.Journal reference:Bakhtiyar Orazbayev, Matthieu Malléjac, Nicolas Bachelard, Stefan Rotter & Romain Fleury. Wave-momentum shaping for moving objects in heterogeneous and dynamic media. Nature Physics, 2024; DOI: 10.1038/s41567-024-02538-5

Table of Contents (click to expand)Sound Navigation And Ranging (SONAR)Active And Passive SONARThe Compromise Between Resolution And Attenuation SONAR is a technique that uses sound waves to map or locate objects in the surrounding environment. The premise is quite simple: first, emit a cluster of sound waves in the direction of an object. While a few waves will bounce off it, the remaining waves will be reflected back in the direction of the emitter. SONAR is a technique that uses sound waves to map or locate objects in the surrounding environment. The premise is quite simple: first, emit a cluster of sound waves in the direction of an object. While a few waves will bounce off it, the remaining waves will be reflected back in the direction of the emitter. If you were to insert one end of a tube into an enormous sea and put an ear to the other, you would definitely look like a loon. However, you would also hear the faint groaning of ships and the singing of various animals far away in the vast depths of the ocean. Leonardo Da Vinci was the first person to perform this ingenious experiment (without the fear of being judged) and discovered this whimsical phenomenon. He had successfully implemented what we now call SONAR. Recommended Video for you:Sonobuoy: How Does This Portable SONAR System Bust Enemy Submarines? Sound Navigation And Ranging (SONAR) SONAR is a technique that uses sound waves to map or locate objects in the surrounding environment. The technique isn’t something extravagant that humans have developed in recent years; it has been used by animals such as bats and whales for millions of years. A bat flying while the sun sets. (Photo Credit: satit_srihin / Shutterstock) The premise is quite simple: first, emit a cluster of sound waves in the direction of an object. While a few waves will bounce off it, the remaining waves will be reflected back in the direction of the emitter. With the knowledge of the speed of sound and the time that passed before the wave was retrieved, an adroit receiver can calculate the object’s distance from the emitter. While Sonar can be implemented in the open air, it is known to be more effective in water. This is because sound waves tend to travel longer distances in water. Owing to Sonar’s remarkable range, whales can discern the shape and movement of objects the size of ping-pong balls from 50 feet away. They are known to rely on Sonar even more than sight to forage and track their kin. A pod of whales. (Photo Credits: Catmando/Shutterstock) Active And Passive SONAR Eventually, humans developed Sonar machines with exponentially superior range and resolution. The simplest of them comprises the combinatorial system of our voice box and ears. It is Sonar that we implement atop mountains and in canyons when we yell at the top of our lungs and eventually hear the echo. However, the LFA Sonar developed by the military emits sound waves that

Travel thousands of miles. Its sweeping range enables us to cover almost 80% of Earth’s oceans by emitting sound waves from only four vantage points! Despite light’s and, for that matter, RADAR’s tremendously superior velocity, it is Sonar that is used by NOAA to develop nautical charts, execute seafloor mapping, locate shipwrecks and predict underwater hazards. In fact, Sonar’s patent was sanctioned after witnessing the events that led to the Titanic’s tragic undoing. Its primary purpose was to identify objects lurking beneath the ocean’s surface in order to avoid underwater collisions. A representation of how ships use SONAR to map seafloors. Subsequently, the first World War brought major advancements that paved the way for underwater surveillance and warfare submarines. Underwater surveillance implements what is known as passive Sonar — a technique that does not require its own transmitter, as it entails listening to sound waves emitted by other transmitters. This means listening to the sounds made by whales and enemy ships. The tool simply detects the sound waves that travel towards it. The machines, however, cannot determine the locations of these transmitters without the help of other passive listening devices. They work in conjunction to triangulate the location of a transmitter, stealthily, without making their presence felt. Submarines transmit sound waves and detect objects in their vicinity by measuring the elapsed time between the reception of the echo. On the other hand, warfare submarines implement active Sonar — a technique that utilizes a receiver as well as a transmitter. This is the technique we most readily associate with Sonar. Submarines transmit sound waves and detect objects in their vicinity by measuring the elapsed time before they receive the echo. Other than merely detecting an object’s presence, the gradual rise of superiorly sophisticated tools has also allowed us to identify the shape, size and orientation in exquisite detail. The Compromise Between Resolution And Attenuation The transmitters are mostly piezoelectric materials, materials that wobble and distort when subjected to an electric current. The production of sound from these distortions is analogous to the vibration of a diaphragm in your speaker. Conversely, piezoelectric materials produce an electric current when subjected to distortion, a property that convinced us to simultaneously employ them as receivers. However, because the reflected waves are waves scattered by an object, one can reasonably conclude that their intensity is diminished compared to the original, incident sound waves. The low intensity of the received waves renders images murky or not suitably bright. The quality of an image, therefore, depends not only on the capabilities of the machine, but also the aspects of the object and the terrain in which the mechanism is implemented. For instance, objects covered with more craggy or irregular surfaces absorb more sound waves than objects covered with regular or smooth surfaces. The propagation of sound waves can also be affected by the temperature of water and the impurities that it fosters. Resolution and range, on the other hand, are characteristics that are intimately linked to the frequency

Monks, who sent sound vibrations to the pit, a reflector of these vibrations. That’s what lifted the boulder 400 meters! The sounds rose smoothly (four minutes, or 240 seconds), were beautiful enough, and the vibrations were harmonious. The result was such a creative effect. It was a creative effect because a sacred temple was being built!The stone took off along a parabola – at first, it went almost vertically (vibrations, reflecting off the rock, did not allow the boulder to approach it), then it began to deviate toward the top. Closer to the rock stood a smaller number of monks on the lines-radiuses, hence, vibrations and their reflections were weaker, and to the top, their number at all began to fall sharply, and the stone, following the path of least resistance, exactly got to the place of erection of the sanctuary!It is likely that in the same way, the ancient builders of the pyramids and other global structures moved unbearable boulders for considerable distances and great heights.To get the latest stories, install our app here.A triumphant experimentPhysicists, in general, allowed the possibility of the existence of controlled acoustic levitation. Not only that, they mastered the technology to control it first in one and then in two planes.Probably, many people had a chance to see macrofilming with a water droplet hovering in the air. Such experiments were performed, for example, by scientists from Switzerland. But nobody managed to achieve three-plane control of the process for a long time.And specialists from the University of Tokyo Yoichi Ochiei, Takayuki Hoshi and Yun Rekimoto made small objects of different shapes and weights float in space with the help of sound waves. Japanese matrices of directional sound emitters, located at specific points, allow them to move along complex trajectories.At first, scientists operated with already familiar water droplets, pieces of polystyrene 0.6 to 2 millimeters in diameter, and small radio elements, but the crowning moment of the series of experiments was when a child’s constructor cube was placed on top of a toy pyramid.Realities and prospectsJapanese experts say that their system of manipulating objects in space has two original features. The force acting on an object is the result of the addition of several directed beams of ultrasonic waves. This produces a standing sound wave and captures its minima and maxima at strictly defined points in space. Using one or more directional emitters, the Japanese change the parameters of this standing sound wave, forcing it to move in space on the trajectory they need, which leads to the movement of the object held by the wave.Specifically, the experiments used four speakers that emit sound waves of over 20 kilohertz, which are inaudible to the human ear