Tunable and label-free bacteria alignment using standing surface acoustic waves.
This paper describes a new technique for focusing bacteria in a microfluidic channel and subsequently controlling their trajectory. Bacteria alignment is obtained using standing surface acoustic waves (SSAW) generated by two interdigitated transducer electrodes (IDTs) patterned on a piezoelectric wafer. The bacteria are focused in the standing wave pressure nodes, separated by half a wavelength, the electrode geometry and applied voltage frequency being chosen accordingly. Interestingly, the position of a pressure node can be modulated by introducing a phase shift between the electrical signals applied to both IDTs. The bacteria, trapped in this node, follow it and can therefore be deflected. This technique works with label-free bacteria in their culture medium and induces low power consumption, which is very interesting for portable devices.
Ecole Centrale Lyon, Ecully, France. sylvain.toru@ec-lyon.fr
S
S
Toru
M
M
Frenea-Robin
N
N
Haddour
F
F
Buret
D016764:Cell Polarity / Q000528:radiation effects*; D002469:Cell Separation / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004926:Escherichia coli / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008846:Micromanipulation / Q000379:methods*; D013016:Sound; D013194:Staining and Labeling