Moving Objects with Precision Using Only Soundwaves

In a groundbreaking innovation, researchers at the École Polytechnique Fédérale de Lausanne (EPFL) have developed a method that uses soundwaves to direct floating objects around obstacles in water. This pioneering approach, inspired by optics, has the potential to revolutionize biomedical applications, such as non-invasive targeted drug delivery.

The concept is rooted in the idea of wave momentum shaping, which was first introduced by Arthur Ashkin, who won the Nobel Prize in Physics in 2018 for his creation of optical tweezers. Optical tweezers use laser beams to manipulate microscopic particles, but they require highly controlled and stable conditions to function effectively. In contrast, the EPFL team has been using soundwaves to manipulate objects in unpredictable, dynamic settings over the past four years.

Led by Romain Fleury, the head of EPFL’s Laboratory of Wave Engineering, the team has been experimenting with soundwaves to move objects in various environments. Instead of trapping objects, they gently push them around, much like guiding a puck with a hockey stick. In their experiments, audible soundwaves emitted from a speaker array guided a floating ping-pong ball along a predetermined path. A second array of microphones captured the feedback as the soundwaves interacted with the ball, allowing researchers to calculate the optimal momentum of the soundwaves in real-time.

The team’s method is based on momentum conservation and is simple and promising. It is 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 consists of speakers and microphones at either end of a water tank, with vertical scattering objects at the center.

To test the effectiveness of their method, the 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 non-invasive and harmless nature.

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 funding secured from the Swiss National Science Foundation (SNSF), they are poised to conduct experiments under a microscope, leveraging ultrasonic waves to precisely manipulate cells at a microscopic level.

This innovative method has the potential to revolutionize the way we approach biomedical applications, and its possibilities are endless.

Historical Context:

The concept of wave momentum shaping, which is the foundation of this innovation, was first introduced by Arthur Ashkin, who won the Nobel Prize in Physics in 2018 for his creation of optical tweezers. Optical tweezers use laser beams to manipulate microscopic particles, but they require highly controlled and stable conditions to function effectively. This breakthrough in optics has now been adapted to use soundwaves, allowing for the manipulation of objects in unpredictable, dynamic settings.

Summary in Bullet Points:

• Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) have developed a method that uses soundwaves to direct floating objects around obstacles in water, inspired by optics. • The concept is based on momentum conservation and is simple and promising, allowing for the movement of objects along a predetermined path, rotation, and control of complex floaters. • The experimental setup consists of speakers and microphones at either end of a water tank, with vertical scattering objects at the center. • The method has been tested in dynamic, uncontrolled environments, such as the human body, and has shown effectiveness in maneuvering objects around stationary and moving obstacles. • The potential applications of this method are groundbreaking, particularly in the fields of biological analysis and tissue engineering, where it can reduce the risk of damage or contamination. • The researchers aim to transition their sound-based experiments from the macro- to micro-scale, leveraging ultrasonic waves to precisely manipulate cells at a microscopic level. • The innovation has the potential to revolutionize the way we approach biomedical applications and its possibilities are endless. • The method is non-invasive and harmless, making it a promising tool for biomedical applications. • The researchers have secured funding from the Swiss National Science Foundation (SNSF) to conduct experiments under a microscope.