Microfluidic surface acoustic wave

Some of the platforms can also be considered as multi-application platforms, which is of special interest in the field of research instrumentation. Here, portability is of less importance, and the number of multiple parameters per sample as well as programmability (potentially also during an assay run) gains impact. The microfluidic large scale integration and the droplet based electrowetting and surface acoustic waves platforms are such versatile examples. 

J. Shi, X. Mao, D. Ahmed, A. Colletti and T. J. Huang, Focusing microparticles in a microfluidic channel with standing surface acoustic waves (SSAW), Lab on a Chip, 8, 221-223 (2008). 

The droplet-based microfluidic platforms for Lab-on-a-Chip applications can be fundamentally divided into two basic setups, the channel-based and the planar surface approach [2]. The channel-based systems are mostly pressure driven with droplet generation and manipulation relying on actuation via liquid flows within closed microchaimels. For the planar surface-based platforms, droplets can be arbitrarily moved in two dimensions representing planar programmable Lab-on-Chips. They are actuated by electrowetting (EWOD) or surface acoustic waves (SAW). 

Surface acoustic wave (SAW) devices are widely used for frequency filtering in mobile communications [1]. Recently published works [2-10] have demonstrated the use of SAWs to manipulate liquid flow in microfluidic devices. A SAW is excited by the application of a radiofrequency (rf) signal to an interdigital transducer (IDT) on a piezoelectric substrate such as quartz or LiNbOs. The... 

Antil H, Heinkenschloss M, Hoppe RHW, Linsenmann C, Wxiforth A (2012) Reduced order modeling based shape optimization of surface acoustic wave driven microfluidic biochips. Math Comput Simul 82(10) 1986-2003... 

Du XY, Swan wick ME, Fu YQ, Luo JK, Hewitt AJ, Lee DS, Maeng S, Milne WI (2009) Surface acoustic wave induced streaming and pumping in for microfluidic applications. J Micromech Microeng 19 035016... 

YeoLY, Friend JR (2009) Ultrafast microfluidics using surface acoustic waves. Biomicrofluidics 3 012002... 

Antil, H., Glowinski, R., 2010. Modehng, simulation and optimization of surface acoustic wave driven microfluidic biochips. J. Comput. Math. 28, 149-169. 

Destgeer, G., et al., 2013. Continuous separation of particles in a PDMS microfluidic channel via travelling surface acoustic waves (TSAW). Lab Chip 13 (21), 4210. Available at http // xlink.rsc. org/ DOI=c3 lc50451d. 

Gantner, A., Hoppe, R., Koster, D., Siebert, K., Wixforth, A., 2007. Numerical simulation of piezoelectricaUy agitated surface acoustic waves on microfluidic biochips. Comput. Visual Sci. 10, 145-161. 

Fig. 2 Microfluidic biosensor chip. Pictorial representation of a piezoelectric bioassay a piezoelectric acoustic wave device (such as a quartz crystal resonator) is coated with a selective, passivating layer to which an analyte-specific receptor can be immobilised. Liquid containing the analyte of interest is then passed across the surface using appropriate microfluidics, which results in selective capture of the analyte. This additional bound material in turn modulates resonance of the acoustic wave device, which is transformed into an electrical signal due to the piezoelectric effect...

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