Acoustic Sensors Using Langmuir-Blodgett Films

Modelling of the response of acoustic piezoelectric resonators in biosensor applications – Part 1: The general theoretical analysis

“…10, 11) can describe, for example, a lipid bilayer membrane covered with the aqueous solution (since the bilayer shows no resistance for in-plane shear deformation and thus behaves as a 2-D liquid) or some other immiscible liquid layers. In the contrast, for the pure elastic thin film considering "dry conditions" (for example, when the resonator operated in gaseous environment) it was found (Kosevich et al, 1995) that the phase velocity shift is proportional to the square of the surface film mass and frequency:…”

“…In the paper we employed our method developed earlier in Kosevich et al (1995) and Voinova et al (1997) and generalized the theory for the case of a viscoelastic thin layer under a bulk liquid (water solution, for example). Such a system has been analysed in details in our earlier works (Voinova et al, 1999(Voinova et al, , 2002Voinova, 2009) for the BAWs excited in the quartz crystal microbalance (QCM).…”

“…Many efforts have been reported in this area since the 1990s (Gulyaev and Plessky, 1997;Gulyaev, 1998;Kalantar-Zadeh et al, 2003a, b;Kosevich et al, 1995;Newton et al, 2001;Powell et al, 2004;Kovacs and Venema, 1992;McHale et al, 2001;Plessky, 1995). The challenge is to include the softness (or viscoelasticity) of the testing material into consideration, specifically, when the resonator operates in a liquid.…”

Dynamics of viscous amphiphilic films supported by elastic solid substrates

“…Measurements of the properties of thin adsorbed films have long constituted an important subfield of interface studies [1][2][3][4][5][6][7][8][9][10]. Scientific and technological applications of thin films, such as Langmuir-Blodgett (LB) films [11][12][13][14][15][16][17][18][19][20], self-assembled monolayers (SAM) [21], and protein monolayers and multilayers [22,23], have stimulated detailed studies of the physical properties of such structures. With these model systems it is possible to construct multilayer amphiphilic films with controlled monolayer thickness h j 25 Å, and to create situations leading to different couplings between the adsorbed film and the chemically modified substrate [12][13][14][15][16].…”

“…Specifically measurements of surface density and viscosity of these films are important both scientifically and, e.g., with respect to their possible application in acoustical biosensors in which they can serve as sensitive elements [13,16,18,19].…”