Ultrasound-assisted levitation: Lab-on-a-drop

Ultrasonic (US) levitation constitutes an alternative for preparing nano-to-pico sample volumes without contamination from solid walls or other external objects, or between samples. More in-depth research on the fundamentals and equipment for implementation of this technique is required (namely, devices for sample and reagent delivery, US levitators, and units for transferring sample or aliquot to the detector and detection systems), as well as on current applications. Comparison with other levitation techniques emphasizes the advantages of US levitation. (c) 2006 Elsevier Ltd. All rights reserved.