Rayleigh surface acoustic wave

Meyer Dos Santos S, et al. A novel p-fluidic whole blood coagulation assay based on Rayleigh surface-acoustic waves as a point-of-care method to detect anticoagulants. Biomicrofluidics 2013 7 56502. 

The simple piezoelectric mass detection systems and the more sensitive surface acoustic wave (SAW) devices operate well in a dry or constant humidity gaseous environment (26,27), but they suffer from loss of signal in aqueous media. In the former case, this is largely a non specific response to water at the surface, and in the latter case it is associated with serious loss of the surface Rayleigh wave to the bulk solution. 

The most commonly known oscillator sensors are bulk acoustic wave (BAW) and surface acoustic wave (SAW) devices. The BAW devices operate according to the Sauerbrey principle that very thin films on AT-cut crystals can be treated as equivalent mass changes of the crystal. The SAW devices can operate either on the Rayleigh wave propagation principle at solid thin-film boundaries [3] or as bulk wave devices [4]. 

Rayleigh wave - A guided elastic wave along the surface of a solid also called surface acoustic wave. 

Surface acoustic wave (SAW) detection involves monitoring the attenuation and changes in velocity of surface sound waves (Rayleigh) in response to the evolution of crystalline size [95Clal]. 

A surface acoustic wave (SAW), also called a Rayleigh wave, is essentially a coupling between longitudinal and shear waves. The energy carried by the SAW is confined near the surface. An associated electrostatic wave exists for a SAW on a piezoelectric substrate, which allows electroacoustic coupling via a transducer. The advantages of SAW technology are 23, 24] ... 

Surface Acoustic Waves. All of the discussion so far has dealt with the propagation of acoustic waves in bulk pol5uners. In addition to longitudinal and shear waves, however, a surface or Rayleigh wave, called a surface acoustic wave, can also be propagated. 

The phenomenon of surface acoustic waves (SAW) first became of interest in the field of geology because the acoustic energy released by earthquakes moves very efficiently as an SAW on the Earth s crust. Lord Rayleigh (15) described the mathematical basis for a surface wave travelling on the earth s... 

Using a ray-tracing technique, one may understand this mechanism understood as follows. The period of this variation results from interference between the two components. Figure 6 shows one component which is spectrally reflected at normal incidence, while the second one undergoes a lateral shift on incidence and reradiates at the critical phase-matching angle for the surface acoustic wave (also referred to as leaky Rayleigh waves ). 

---