September 29, 2010 Wednesday 15:30
Kürşat Araz, Cornell University
Nonlinear Acoustical Interactions in Microfluidic Systems… A poor cat's dream after the "Pied Piper of Hamelin"

Acoustic waves exhibit manipulative effects on the matter through two nonlinear phenomena: acoustic streaming and acoustic radiation pressure force. Despite their century long history, their use in technology was limited due to problems in efficiency and scalability of the force range. Recently, as a promising solution to the problem of micro and nano particle handling in “Lab on a Chip” microfluidic devices, interest in these nonlinear acoustical phenomena is increasing. By using a glass capillary attached to a piezoelectric Lead Zirconate Titanate (PZT) plate, generation of extreme subwavelength acoustical modes inside the microfluidic glass capillary - even at few volts of voltage drive- has been demonstrated. These modes generate 2 dimensional acoustic force traps inside the capillary leading to controlled micro and nano particle collection, separation and mixing in a single device mechanism without use of any other specific methods such as magnetic beads or electrophoretic interactions. Presented actuator mechanism enables battery operated, inexpensive, portable microfluidic systems which may lead to the production of cost efficient point of care diagnostic devices. Wide range of applications on colloidal micro and nano particles and biological samples such as blood, bacteria and cells will be presented during the talk.