Applications/Results

In a microgravity environment, acoustic levitation offers tremendous potential for intricate fabrication technology. With the dominant gravitational force removed, fine control can be exerted on the acoustic field and the resulting movement and deposition patterns of the particles. The particles can be solid or liquid. Thus, for example, we can induce resins to harden along carefully-specified, intricate surfaces inside a structure, with no need for access or machining.

It is possible to imagine intricate sound field tailoring schemes, to form desired internal structures with specific materials. This would open up an exciting field of manufacturing. Stretching the imagination, we may one day be able to learn how to form ("grow") complex internal structures such as those in living beings or bio-robots, instead of building them up from thousands of assembled parts. Or on a simpler level, basic molds today are limited to what their product. With acoustic shaping, all that is needed to go from one shape of mold to the other is simply changing the sound input, which will thus alter the locations of minimum potential.

We obtained surfaces, and their curvature depeneded on the type of sound wave and frequency we used. Performing preliminary data analysis on our data collected from our two flight-tests, we discovered that we were able to produce a single frequency wave in our box followed by weaker waves having a frrequency being a multiple of the driving frequency. That was done using Fast Fourier Transformations (FFT).

Our next goal is to perform a Spatial Correlation Velocimetry (SCV), that will enable us to understand the potential produced by the drag which is induced by the interaction of the particles with the air-velocity fluctuations.