A drop can remain motionless in the air without wires or magnetic fields. Sound waves can exert sufficient force to compensate for its weight. A transmitter and a reflector make it possible to create an acoustic field where small objects remain trapped. Sound then becomes a means of manipulating matter.
In 2013, a team from ETH Zurich presented a system capable of moving several drops and particles in a plane. The researchers changed the acoustic field in space and time. They could bring two drops together to mix them, or put a soluble coffee particle in contact with a drop of water, without depositing them on a table.
The principle avoids some unwanted interactions with the walls of a container. It does not allow you to lift any object by simply increasing the volume of a speaker: dimensions and settings count. But at this scale, a force usually associated with what we hear becomes able to organize a small suspended laboratory.
What we know
Demonstrations use a specially controlled acoustic field.
To go to the source
References consulted on September 21, 2026. Linked pages may be in another language.
Signaler une erreur ou apporter une précision
