Acoustic Concentration Of Particles In Fluid Flow
An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.
1 . A method, comprising:
applying an acoustic radiation pressure to a population of particles disposed in a medium within a fluid flow channel,
wherein the fluid flow channel is at least partially defined by a surface of a material configured to act as a pressure release surface, and wherein the acoustic radiation pressure is applied with a vibration generator disposed opposite the material so as to give rise to a pressure node, and
the acoustic radiation pressure being applied as to give rise to one or both of:
(a) an accumulation of one or more particles with positive acoustic contrast, if present, at the surface of the material, or
(b) an accumulation of one or more particles with negative acoustic contrast, if present, in the direction of the vibration generator relative to the surface of the material.
2 . The method of claim 1 , wherein the material is characterized as acoustically transparent.
3 . The method of claim 1 , further comprising optically inspecting one or more of the accumulation of positive acoustic contrast particles at the surface of the material.
4 . The method of claim 1 , further comprising optically inspecting one or more of the accumulation of negative acoustic contrast particles in the direction of the vibration generator relative to the surface of the material.
5 . The method of claim 1 , further comprising separating particles outside the accumulation of positive acoustic contrast particles at the surface of the material.
6 . The method of claim 1 , further comprising separating particles outside the accumulation of negative acoustic contrast particles in the direction of the vibration generator relative to the surface of the material.
7 . The method of claim 1 , further comprising washing one or more of the accumulation of positive acoustic contrast particles at the surface of the material, exposing one or more of the accumulation of positive acoustic contrast particles at the surface of the material to one or more reagents, or both.
8 . The method of claim 7 , wherein the one or more reagents are diffused through the material.
9 . The method of claim 1 , further comprising washing one or more of the accumulation of negative acoustic contrast particles in the direction of the vibration generator relative to the surface of the material, exposing one or more of the accumulation of negative acoustic contrast particles in the direction of the vibration generator relative to the surface of the material to one or more reagents, or both.
10 . The method of claim 9 , wherein the one or more reagents are diffused through the material.
11 . The method of claim 1 , further comprising changing a frequency of the vibration generator so as to change a location of the pressure node, to give rise to a pressure node, or both.
12 . The method of claim 11 , further comprising changing a frequency of the vibration generator so as to change a location of the pressure node.
13 . A system, comprising:
a fluid flow channel having an inlet and an outlet,
the fluid flow channel being at least partially defined by a surface of a material configured to act as a pressure release surface;
a vibration generator configured to, during operation, effect an acoustic radiation pressure that produces an acoustic displacement field within a medium disposed within the fluid flow channel,
the acoustic displacement field being applied to as to give rise to one or both of:
(a) an accumulation of one or more positive acoustic contrast particles, if present in the medium, at the surface of the material, or
(b) an accumulation of one or more negative acoustic contrast particles, if present in the medium, in the direction of the vibration generator relative to the surface of the material.
14 . The system of claim 10 , further comprising an imager configured to image one or more particles accumulated at the surface of the material.
15 . The system of claim 10 , further comprising an imager configured to image one or more particles accumulated in the direction of the vibration generator relative to the surface of the material.
16 . The system of claim 10 , wherein the material is optically transparent.
17 . The system of claim 10 , wherein the material is permeable.
18 . The system of claim 17 , wherein the material is selectively permeable.
19 . The system of claim 10 , further comprising a channel configured to receive particles outside an accumulation of one or more positive acoustic contrast particles at the surface of the material.
20 . The system of claim 10 , further comprising a channel configured to receive particles outside an accumulation of one or more negative acoustic contrast particles, if present in the medium, in the direction of the vibration generator relative to the surface of the material.