US 11,731,127 B2
Acoustic tweezers
Michaël Aymeric Baudoin, Lezennes (FR); Olivier Khalil Bou Matar-Lacaze, Saint Amand les Eaux (FR); Antoine Jean-Pierre Riaud, La Roche sur Yon (FR); and Jean-Louis Pierre Thomas, Montgeron (FR)
Assigned to CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE, Paris (FR); UNIVERSITÉ DE LILLE, Lille (FR); ECOLE CENTRALE DE LILLE, Villeneuve d'Asq (FR); and SORBONNE UNIVERSITE, Paris (FR)
Appl. No. 16/85,424
Filed by CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE, Paris (FR); UNIVERSITÉ DE LILLE, Lille (FR); ECOLE CENTRALE DE LILLE, Villeneuve d'Asq (FR); and SORBONNE UNIVERSITE, Paris (FR)
PCT Filed Mar. 15, 2016, PCT No. PCT/EP2016/055611
§ 371(c)(1), (2) Date Sep. 14, 2018,
PCT Pub. No. WO2017/157426, PCT Pub. Date Sep. 21, 2017.
Prior Publication US 2019/0091683 A1, Mar. 28, 2019
Int. Cl. B01L 3/00 (2006.01); G02B 21/32 (2006.01); G01N 15/14 (2006.01); H03H 9/145 (2006.01)
CPC B01L 3/502715 (2013.01) [B01L 3/50273 (2013.01); B01L 3/502761 (2013.01); G01N 15/1404 (2013.01); G02B 21/32 (2013.01); H03H 9/14505 (2013.01); B01L 2200/0668 (2013.01); B01L 2400/0436 (2013.01); G01N 2015/142 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An electroacoustic device comprising a transducer comprising a piezoelectric substrate, first and second electrodes of inverse polarity comprising respective first and second tracks provided on said substrate, the first and second tracks spiraling around a same center, the transducer being configured for generating a swirling ultrasonic surface wave in the substrate, wherein each of the first and second tracks spirals along a line defined by the equation

OG Complex Work Unit Math
wherein:
R(θ) is the polar coordinate of the line with respect with the azimuthal angle θ,
φ0 is a free parameter,
l is the vortex order of a swirling SAW of pulsation ω, l being an integer such that |l|≥1.
μ0(θ) is given by:

OG Complex Work Unit Math
where zi−zi-1 is the distance between two successive interfaces separating materials stacked onto the substrate, z0 being the height of the interface between the substrate and the layer contacting the substrate, μ0(θ)=0 in case of the absence of stacked layers

OG Complex Work Unit Math
where ψ depends on Θ as follows:

OG Complex Work Unit Math
sr(ψ) is the wave slowness on the surface plane of the substrate in the direction of propagation ψ, and sz(ψ) is the wave slowness in the out of plane direction, a wave slowness in a direction i being r or z being computed from the wavenumber ki as sr(ψ)=kr(ψ)/ω: and sz(ψ)=kz(ψ)/ω
sr′(ψ) is the derivative of sr(ψ) in respect to the direction of propagation,
α(ψ) is the phase of the vertical motion of the wave propagating in direction ψ versus the associated electric field.