News

Dances with waves: breakthrough in moving small objects using acoustics

By playing carefully constructed melodies, the scientists can simultaneously move multiple objects on the plate towards desired targets.

Researchers move multiple objects simultaneously and independently on a plate by playing carefully chosen musical notes. Video:  Quan Zhou, Kourosh Latifi

Researchers of Aalto University have made a breakthrough in controlling the motion of multiple objects on a vibrating plate with a single acoustic source. By playing carefully constructed melodies, the scientists can simultaneously and independently move multiple objects on the plate towards desired targets. This has enabled scientists, for instance, writing words consisting of separate letters with loose metal pieces on the plate by playing a melody.

Already in 1878, the first studies of sand moving on a vibrating plate were done by Ernst Chladni, known as the father of acoustics. Chladni discovered that when a plate is vibrating at a frequency, objects move towards a few positions, called the nodal lines, specific to that frequency. Since then, the prevailing view has been that the particle motion is random on the plate before they reached the nodal line. “We have shown that the motion is also predictable away from the nodal lines. Now that the object does not have to be at a nodal line, we have much more freedom in controlling its motion and have achieved independent control of up to six objects simultaneously using just one single actuator. We are very excited about the results, because this probably is a new world record of how many independent motions can be controlled by a single acoustic actuator,” says Professor Quan Zhou.

We are very excited about the results, because this probably is a new world record of how many independent motions can be controlled by a single acoustic actuator.

The objects to be controlled have been placed on top of a manipulation plate, and imaged by a tracking camera. Based on the detected positions, the computer goes through a list of music notes to find a note that is most likely to move the objects towards the desired directions. After playing the note, the new positions of the objects are detected, and the control cycle is restarted. This cycle is repeated until the objects have reached their desired target locations. The notes played during the control cycles form a sequence, a bit like music.

Image: Quan Zhou

The new method has been applied to manipulate a wide range of miniature objects including electronic components, water droplets, plant seeds, candy balls and metal parts. “Some of the practical applications we foresee include conveying and sorting microelectronic chips, delivering drug-loaded particles for pharmaceutical applications or handling small liquid volumes for lab on chips,” says Zhou. “Also, the basic idea should be transferrable to other kinds of systems with vibration phenomena. For example, it should be possible to use waves and ripples to control floating objects in a pond using our technique.”

The article has today been published on Nature Communications. DOI: 10.1038/ncomms12764

Contact details:
Professor Quan Zhou
Aalto University (Finland)
Tel. +358 40 855 0311
[email protected]

 

  • Published:
  • Updated:
Share
URL copied!

Related news

Mallinnus aerosolien leviämisestä bussissa.
Press releases, Research & Art Published:

New simulation code to eliminate need for super computers in modelling indoor aerosols

Focused on public indoor environments, the code will be openly available for researchers and other professionals
Research & Art Published:

BEYOND MATTER aims to develop novel solutions for the accessible documentation and presentation of exhibitions

BEYOND MATTER is an international, interdisciplinary project on the revival of past landmark exhibitions, the documentation of current exhibitions and the dissemination of documentation along with actual artworks –
both materially and immaterially present – in innovative ways.
Research & Art Published:

SPICE promotes social cohesion by citizen curation of cultural heritage

An EU-H2020 funded SPICE aims to promote social cohesion by researching and developing tools and methods to support citizen curation with groups at risk of exclusion to actively interact and participate in a shared culture.
UNITE! workshop at Aalto University in February 2020. Photo: Mikko Raskinen.
Research & Art Published:

Funding for project to design future universities

Europe-wide collaboration aims to make research more open and diverse