Optimal design of siliconbased chips for piezoinduced ultrasound resonances in embedded microchannels
(2015) ICU International Congress on Ultrasonics, ICU 2015 In Physics Procedia 70. p.5054 Abstract
We present a variational formulation of the governing equations and introduce global indicators to describe the behavior of acoustofluidic devices driven at resonance frequencies by means of a piezoelectric transducer. The individuation of the correct Lagrangian densities for the different parts constituting the device (the piezo transducer, the silicon walls, the fluidfilled microchannel, and the glass lid) allows for the introduction of the weak formulation used in the finite element discretization of the equations describing the system in its oscillatory regime. Additionally, the knowledge of the Lagrangian density leads to the derivation of the correct structure of the Hamiltonian density, i.e. the energy density, which is... (More)
We present a variational formulation of the governing equations and introduce global indicators to describe the behavior of acoustofluidic devices driven at resonance frequencies by means of a piezoelectric transducer. The individuation of the correct Lagrangian densities for the different parts constituting the device (the piezo transducer, the silicon walls, the fluidfilled microchannel, and the glass lid) allows for the introduction of the weak formulation used in the finite element discretization of the equations describing the system in its oscillatory regime. Additionally, the knowledge of the Lagrangian density leads to the derivation of the correct structure of the Hamiltonian density, i.e. the energy density, which is important for the quantification of the energy content of the whole system and its individual parts. Specifically, the energy content of the embedded microchannel is quantified by means of the acoustofluidic yield η defined as the ratio between the energy in the channel and the total energy. From the standpoint of acoustophoretic application, the introduction of the acoustophoretic mean orientation allows us to identify the frequencies for which an acoustophoretic effect, i.e. the lateral motion of particle dragged by the axial main flow, is particularly strong. Finally, the connection between the mechanical and electrical degrees of freedom of the system is addressed. This is important for proper determination of the dissipated power, and it may lead to the detection of resonance states by means of purely electrical measurements. Numerical simulations and preliminary experimental results show some features of the model introduced.
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 author
 Garofalo, F. ^{LU} ; Laurell, T. ^{LU} and Bruus, H.
 organization
 publishing date
 2015
 type
 Chapter in Book/Report/Conference proceeding
 publication status
 published
 in
 Physics Procedia
 volume
 70
 pages
 5 pages
 publisher
 Elsevier
 conference name
 ICU International Congress on Ultrasonics, ICU 2015
 external identifiers

 Scopus:84948675626
 DOI
 10.1016/j.phpro.2015.08.039
 language
 English
 LU publication?
 yes
 id
 d9dc8e680ef0439d8b381200885122c0
 date added to LUP
 20160627 10:23:44
 date last changed
 20160923 15:15:50
@misc{d9dc8e680ef0439d8b381200885122c0, abstract = {<p>We present a variational formulation of the governing equations and introduce global indicators to describe the behavior of acoustofluidic devices driven at resonance frequencies by means of a piezoelectric transducer. The individuation of the correct Lagrangian densities for the different parts constituting the device (the piezo transducer, the silicon walls, the fluidfilled microchannel, and the glass lid) allows for the introduction of the weak formulation used in the finite element discretization of the equations describing the system in its oscillatory regime. Additionally, the knowledge of the Lagrangian density leads to the derivation of the correct structure of the Hamiltonian density, i.e. the energy density, which is important for the quantification of the energy content of the whole system and its individual parts. Specifically, the energy content of the embedded microchannel is quantified by means of the acoustofluidic yield η defined as the ratio between the energy in the channel and the total energy. From the standpoint of acoustophoretic application, the introduction of the acoustophoretic mean orientation allows us to identify the frequencies for which an acoustophoretic effect, i.e. the lateral motion of particle dragged by the axial main flow, is particularly strong. Finally, the connection between the mechanical and electrical degrees of freedom of the system is addressed. This is important for proper determination of the dissipated power, and it may lead to the detection of resonance states by means of purely electrical measurements. Numerical simulations and preliminary experimental results show some features of the model introduced.</p>}, author = {Garofalo, F. and Laurell, T. and Bruus, H.}, language = {eng}, pages = {5054}, publisher = {ARRAY(0x9ad4948)}, series = {Physics Procedia}, title = {Optimal design of siliconbased chips for piezoinduced ultrasound resonances in embedded microchannels}, url = {http://dx.doi.org/10.1016/j.phpro.2015.08.039}, volume = {70}, year = {2015}, }