Toothpick Surfing on Acoustic Waves and Other Levitation Implications

Toothpick Surfing on Acoustic Waves

Acoustic waves have allowed for many more objects and liquids to be levitated in mid-air than ever before. Such feats are usually performed with magnets, but the objects floating on the magnets needed to have magnetic properties. ETH, a group of researchers in Zurich, successfully levitated a toothpick in mid-air and controlled its movements using acoustic waves. With the same technique they also merged droplets of liquid.

The postdoctoral researcher involved in this study at the Swiss Federal Institute of Technology is Daniele Foresti. Foresti made it possible for any object, regardless of its properties, (except maybe weight which is still at the experimental stage) to levitate in mid-air through the use of acoustic waves. This allows for the study of some chemical reactions involving processes that would otherwise be compromised with the contact of a surface.

Levitation via acoustic waves allows for a vast number of objects and liquids to be experimented on. The current methods we have that allow objects to reach a levitated state are magnetic levitation, electrical fields, and suspension in liquids with the help of buoyancy. The problem with magnets is the difficulty of controlling the movement of liquids. The liquids are required to have some sort of magnetic properties. Floating liquids in another liquid requires the use of immiscible liquids (not forming a homogeneous mixture when added together) such as oil and water. Acoustic waves take care of these limitations. The only limitation is the maximum diameter of the object being levitated. It has to correspond with half the acoustic wavelength being used. Levitation is achieved when all of the acting forces (gravity and acoustic waves) reach equilibrium. The force of the acoustic waves counteracts the force of gravity, which allows this state to occur.

Making Coffee on Acoustic Waves

The scientific term used to describe this phenomenon is the acoustic radiation pressure effect. This is not a new discovery, rather an alteration to a previous one that goes back to the findings of Rayleigh. However, unlike in previous studies, we can now control movement with acoustic waves. This was done by putting together multiple modules that create the acoustic waves and by switching them on to vary their wave action. This varying process is how liquid is able to move from one module to the next. Foresti used this method to merge a water droplet and a bit of instant coffee together to form coffee!



Bubble Boy Eat Your Heart Out: Bubble Dome Camping and Living


Have you ever gotten the question, “Do you live in a bubble?” That phrase has always frustrated me personally since it implies that I have no knowledge of topics or of the outside world, but now I fear it NOT!

BubbleTree has developed bubble tents, tree houses, lodges and huts which allow campers and nature enthusiasts alike to enjoy views from the inside of a transparent dome. Similar in design to the containment laboratory used in the new blockbuster film Thor, the spheres have an air renewal system that will keep the user comfortable and full of oxygen while they go about their daily indoor activities.

The very intelligent design of the bubble tent helps reduce noises of the outside world, allowing for the user to get a good night’s sleep, even if the bubble is set up next to roaring waves on a beach front. The inside however is created in such a shape that it will actually amplify noises through echoes, passionate lovers beware. BubbleTree talks about the technique and thought behind theses bubble creations:

Designed by Pierre Stephane Dumas, this approach is based on the following basis: Minimum energy, minimum materials, maximum comfort, and maximum interaction with the environment.

Want a life-sized snow globe? No problem. A 2 room suite with a bathroom while you bird-watch? They have you covered. Bringing your kids along? That bathroom is now a kids room instead. Silly, is it not? Check out some of these fancy French examples of ways these crafty bubble tents can be used! You may be even tempted to use your bubble hut in creative ways at a concert.

My question is when are they going to make these bad boys hover around and provide us consumers with a view of cities and landscapes, maybe with the use of propellers.. oh right, helicopters.

So the next time someone asks you if you live in a bubble, burst THEIR bubble and respond why yes, and the view is extraordinary. Bubble boy eat your heart out.