Acoustofluidic device

Patent metadata

Field	Value
Publication number	US-2022193663-A1
Application number	US-202017599703-A
Country	US
Kind code	A1
Filing date	Mar 26, 2020
Priority date	Apr 2, 2019
Publication date	Jun 23, 2022
Grant date	—

Abstract

The invention concerns a novel acoustofluidic device to separate acoustically active particles from fluids comprising a novel device arrangement for improved acoustic pressure and particle velocity; and a method of separating particles from a fluid comprising use of same.

First claim

1 . An acoustofluidic device comprising:
at least one interdigitated transducer (IDT) deposited on the surface of a piezoelectric substrate; and functionally coupled therewith at least one channel having a first end and second end forming a fluid flow path, wherein said at least one channel is positioned adjacent said at least one IDT and comprises a first sidewall; a second sidewall; a floor and an acoustic wave source defining a roof of the at least one channel.

2 . The device according to claim 1 comprising at least a pair of interdigitated transducers (IDTs) deposited on the surface of a piezoelectric substrate to form at least one standing surface acoustic wave (SSAW) transducer wherein the at least one channel is positioned between said at least one pair of IDTs.

3 . The device according to claim 1 , wherein said piezoelectric substrate is: polyvinylidene difluoride (PVDF), gallium nitride (GaN), Aluminum nitride (AlN), silicon carbide (SiC), aluminum gallium nitride (AlGaN), Langasite (La3Ga5SiO 14 ), gallium orthophosphate (GaPO 4 ), a lithium niobate (LiNbO 3 ), lithium tantalate (LiTaO 3 ), barium titanate (BaTiO 3 ), lead zirconate titanate (Pb[Zr x Ti 1-x ]O 3 with 0≤x≤1), potassium niobate (KNbO 3 ), sodium tungstate (Na2WO 3 ), or zinc oxide (ZnO).

4 . (canceled)

5 . The device according to claim 1 , wherein a longitudinal axis of said at least one channel is substantially orthogonal with respect to said at least one IDT or is provided at an angle with respect to said at least one IDT.

6 . (canceled)

7 . (canceled)

8 . The device according to claim 1 , wherein said at least one channel floor and/or sidewalls is manufactured from: polycarbonates or polymethyl methacrylates, polyphenylsulfone (PPS), glass, silicone, ceramic, elastomers, thermoset polyester (TPE), poly-methyl methacrylate (PMMA), polystyrene (PS), polycarbonate (PC), poly-ethylene glycol diacrylate (PEGDA), teflons, polyurethane (PU), paper, hydrogels, pyrex or polydimethyl siloxane (PDMS).

9 . (canceled)

10 . The device according to claim 1 , wherein said acoustic wave source is provided as a further (a) at least one interdigitated transducer (IDT) deposited on the surface of a piezoelectric substrate, (b) a standing surface acoustic wave (SSAW) transducer, or both.

11 . (canceled)

12 . The device according to claim 10 , wherein said at least one IDT deposited on the surface of a piezoelectric substrate and said acoustic wave source are configured such that, in use, a phase difference of between about Δφ=π/2 and Δφ=3π/2 exists between the acoustic wave(s) originating in said piezoelectric substrate and the acoustic wave(s) originating in said roof of the at least one channel.

13 . The device according to claim 12 wherein, in use, a phase difference of between about Δφ=π exists between the acoustic wave(s) originating in said piezoelectric substrate and the acoustic wave(s) originating in said roof of the at least one channel.

14 . The device according to claim 1 , wherein said acoustic wave source is provided as a bulk acoustic wave (BAW) piezoelectric transducer producing bulk acoustic waves (BAWs).

15 . The device according to claim 14 wherein said BAW piezoelectric transducer is a piezoelectric ceramic.

16 . The device according to claim 15 wherein said piezoelectric transducer is PZT or LiNbO 3 .

17 . The device according to claim 1 , wherein said at least one channel has a width to height ratio of between about 10:1 and 1:1.

18 . The device according to claim 1 , wherein said at least one channel has a width between about 10-1000 μm and a height between about 1-250 μm including every 1 μm therebetween.

19 . The device according to claim 1 , wherein the at least one channel comprises at least one inlet configured to introduce a fluid into a proximal end portion of the at least one channel and/or at least one outlet which is located at a downstream portion of the at least one channel positioned substantially along the longitudinal axis of the at least one channel.

20 . The device according to claim 19 wherein the at least one inlet and/or the at least one outlet is branched to permit separation of particles into different flow streams.

21 . The device according to claim 1 , wherein said device comprises a plurality of channels in fluid communication with one another.

22 . The device according to claim 21 wherein each of the plurality of channels is functionally coupled with at least one IDT deposited on the surface of a piezoelectric substrate or a standing surface acoustic wave (SSAW) transducer such that each channel can separate different particles with respect to one another according to a standing wave generated for each respective channel.

23 . The device according to claim 1 , wherein the at least one IDT or a standing surface acoustic wave (SSAW) transducer and/or acoustic wave source can generate a resonance frequency, or a mean resonance frequency, of between about 100 KHz to 1000 MHz.

24 . (canceled)

25 . A method for separating a mixture of acoustically active particles comprising:
suspending a mixture of acoustically active particles in a liquid flow stream; and flowing said liquid flow stream through the at least one channel of the device of claim 1 , thereby separating the mixture of acoustically active particles.

26 . An apparatus, comprising:
a signal generator configured to couple to an acoustofluidic device having (i) at least one interdigitated transducer (IDT) deposited on the surface of a piezoelectric substrate and (ii) at least one channel coupled to the IDT, wherein the at least one channel has a first end and second end forming a fluid flow path and wherein the at least one channel is positioned adjacent the at least one IDT and includes a first sidewall, a second sidewall, a floor, and an acoustic wave source defining a roof of the at least one channel; wherein the signal generator is configured to produce a radio frequency (RF) voltage for the at least one IDT that controls a distribution of an acoustic pressure field within the at least one channel.

Assignees

• Univ College Cardiff Consultants Ltd

Inventors

• Yang Xin

Classifications

• B01L2400/0439

  ultrasonic vibrations, vibrating piezo elements · CPC title

• B06B1/0238

  of a single frequency, e.g. a sine-wave · CPC title

• B06B1/0644

  using a single piezoelectric element (B06B1/0688 takes precedence) · CPC title

• B01L3/50273 Primary

  characterised by the means or forces applied to move the fluids · CPC title

• B01L2400/0436

  acoustic forces, e.g. surface acoustic waves [SAW] · CPC title