Message in a Bottle: Scientists Cap Sound Waves
Message in a Bottle: Scientists Cap Sound Waves
Science has the power to guide us only if we constantly hone and develop inventions and innovations. Scientists have found a way to "bottle" sound waves through a technique for generating acoustic bottles in the open air. This can bend the paths of sound waves across prescribed trajectories. Sound waves move in a manner which is similar to sound waves. They travel along distances in straight lines till they meet an object.
The path through reflection/refraction/diffusion can be bent and this is the basis on which ultrasound medical imaging can be accomplished along with non-destructive testing of materials. In current times, scientists have found a way to bend the path of sound waves to meet difficult demands as per the requirements for super high-resolution imaging and other applications. While "metamaterials" have been used to bend sound waves sufficiently, there is a limit on their application on account of the nature of the materials.
Scientists therefore decided to observe sound waves so that they could create a new technique. They worked towards developing an acoustic bottle featuring a 3-D curved shell. A wall of high acoustic pressure surrounds the null pressure region across the middle and the sound waves which form across the bottle are concentrated into a beam that reaches through the high pressure wall of the curved shell.
"We need to find ways to bend acoustic wave fields without depending on the use of a highly engineered medium," said Xiang Zhang, director of Berkeley Lab's Materials Sciences Division has stated in a media release and he has added that "With our bottle beam technique, we can design and synthesize acoustic bottles that are capable of directing sound waves along paths of desired curvature through homogeneous space without the need of metamaterials or any other highly engineered medium."
These bottle beams can yield a lot of positive outcomes for researchers. They can open up new avenues for applications where hard to access objects can be hidden behind obstacles such as acoustic imaging as well as therapeutic ultrasound via in homogenous media. Additionally the acoustic bottle could also be used as a cloaking device through re-routing of sound waves across an object. The author of this research paper Sui Yang has been quoted as saying that "These giant acoustic traps could lead to new technologies and devices for a variety of applications in chemistry, materials, as well as biosciences".
This technique has numerous applications in fields such as acoustic cloaking as well as ultrasonic imaging and sonic levitation along with particle manipulation. Scientists at University of California-Berkeley have produced these sound bottles that can redirect the wave swith amazing precision. The researchers bent sound waves through acoustic transducers which operate at a frequency of 10 KHz and the array was able to alter the phase and direction in which the sound wave was generated. A defined set of pressure fields with distinct and specific trajectories have been created in the air.
