One key to the difference lies in the operating wavelength of each system. Sonication has a wavelength of 10's of centimeters. This is a fundamental constraint as a typical sample processing tube used in a laboratory environment will be anywhere from 10 to 100mm long with the sample occupying typically less than 20mm in height. It is therefore impossible to precisely control the waveform in this sample with a 100mm wavelength. This results in unfocused, long wavelength sonication energy scattering, reflecting, and in many instances producing "hot spots" which may readily damage some biological or chemical sample types. In other words, the energy is not correctly scaled to the sample. In contrast, AFA wavelengths are scaled to the process. For example, in a 96 well plate of ~3mm inner diameter wells, the wavelength is approximately 1mm. This allows AFA to be focused into a localized area of the sample. The wavelength difference is in excess of 100 fold.

The Isothermal Advantage

Another benefit of AFA is that the processes may be run isothermally. This is also not the case with sonication energy which is known to pump large degrees of heat into samples. Again, this is related to the intrinsic physical properties of the low frequency, long wavelength process. Yet another benefit of AFA is the controlled convergence of the mechanical energy. A shorter wavelength, coupled with controlled wave packets, enables the energy to traverse materials, such as sample tubes, prior to achieving a peak energy density inside of a sample tube.