Tractor beam can move macro-scale objects with sound

The future is here! Geek has the story on these so called “tractor beams” and how they work.

“Tractor beams” are mostly mentioned in reference to starships; the phrase has probably been uttered more by science fiction characters than by everyone else combined. As a result, a new acoustic tractor beam recently unveiled in the journal Physical Review of Letters might not be quite what you’re expecting; since there’s no air between two starships, and thus no possibility of sound, an acoustic tractor beam could never work in space. Still, the breakthrough technology could find dozens of useful applications here on Earth, and pave the way for other, more space-friendly solutions.

The physics at work here is both simple and complex, a dizzying confluence of wave mathematics that ultimately sum to allow the team to create a simple pulling force with sound. Sound, by the way, is simply vibrations in a medium (usually air), and those vibrations manifest as regions of greater or lesser air pressure; the peak of a sound wave diagram corresponds to an area of high pressure, while the trough represents an area of low pressure. These expansions and contractions in a physical medium can do work when they interact with an object — just hold your hand up to a powerful subwoofer to assure yourself of that…

…Now, by shaping the object to be moved so it interacts specifically with the waves doing the moving, this team has managed to move a centimeter-scale object with sound. That’s millions of times larger than the objects we’ve managed to move with light waves, which have never exceeded the nanometer scale. By setting the angle and frequency of vibrations just right, this experiment created a low pressure zone in front of the object, pulling it forward, while simultaneously bouncing waves off the back end to push from the other side. The object used in this experiment was triangular, so the angled back end could transfer up as much kinetic energy forward as possible.

This study used a tank of water for its experiment, rather than of air, largely because water is denser than air and thus allows better propagation of waves. This means their waves will lose less power as they travel and, far more importantly, they will carry more kinetic energy. In theory the technique should work just as well in air, but would result in a great reduction in overall pulling power.

This breakthrough could be of use to a wide array of sectors in research and industry. Moving small objects in a liquid medium could be useful to extremely fine surgical procedures, like small-scale modifications to the cornea. Sending specialized waves through a complex medium should only affect the objects specifically designed to interact with those waves, and as such should not both the rest of, say, your eye. On the other hand, complex environments also have more structures for waves to bounce off, thus making the whole process more difficult.

Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join over 36,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org

Maker Business — “Packaging” chips in the US

Wearables — Enclosures help fight body humidity in costumes

Electronics — Transformers: More than meets the eye!

Python for Microcontrollers — Python on Microcontrollers Newsletter: Silicon Labs introduces CircuitPython support, and more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Guardian Robot, Weather-wise Umbrella Stand, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — #NewProds 7/19/23 Feat. Adafruit Matrix Portal S3 CircuitPython Powered Internet Display!