Abstract: Technologies for harmonic acoustic manipulation of colloidal particles include a system having a piezoelectric substrate coupled to one or more segmented acoustic transducers and a fluid positioned above the substrate. The segmented transducers have multiple segments, each with a resonant frequency equal to a harmonic frequency. The system further includes a controller that generates a harmonic signal including multiple harmonic components and applies the signal to the segmented acoustic transducers to generate an acoustic potential field in the fluid and manipulate the colloidal particles. The system may translate or rotate the particles, and may form the particles into a colloidal crystal monolayer. The system may selectively pair or otherwise group and separate individual particles. The system may pair and separate multiple groups of particles. The system may measure adhesion between particles. The system may pattern particles over a surface. The colloidal particles may be cells.

Abstract: Technologies for acoustoelectronic manipulation of micro/nano particles include a system having a piezoelectric substrate coupled to one or more acoustic transducers and a fluid layer positioned above the substrate. Micro/nano particles are introduced to the fluid, which can be in the form of a droplet or in a confined channel, and a signal is applied to the acoustic transducer. One or more parameters of the signal are varied after introducing the micro/nano particles into the fluid. The parameters may include amplitude, frequency, or phase of the signal. The system may include one or more acoustic transducers. Multiple signals may be applied to the acoustic transducers. Wave superposition of acoustic waves in the substrate manipulates micro/nano particles in the fluid. The nanoparticles may include carbon nanotubes, nanowires, nanofibers, graphene flakes, quantum dots, SERS probes, exosomes, vesicles, DNA, RNA, antibodies, antigens, macromolecules, or proteins.

Abstract: Acoustofluidic systems including acoustic wave generators for manipulating fluids, droplets, and micro/nano objects within a fluid suspension and related methods are disclosed herein. According to an aspect, an acoustofluidic system includes a substrate including a substrate surface. The system also includes an acoustic wave generator configured to generate acoustic streaming within an acoustic wave region of the substrate surface. Further, the acoustic wave generator is controllable to change the acoustic streaming for movement of a droplet or other micro/nano object on a fluid suspension about the acoustic wave region.

Abstract: The present disclosure provides for acoustofluidic centrifuge systems that can enrich and separate nanoparticles disposed in a fluid, such as liquid droplets, in a fast and efficient manner. Exemplary systems include a sound wave generator, such as a pair of slanted interdigitated transducers, and a containment boundary, such as a PDMS ring. The sound wave generator can produce surface acoustic waves that are capable of driving droplets to spin in a manner that can separate different sized particles into groups. In some embodiments, the acoustofluidic centrifuge system can include a plurality of containment boundaries in fluid communication with each other, allowing particles to separate between the containment boundaries. Methods of operating such systems, including methods of isolating different exosome subpopulations, are also disclosed.

Abstract: Acoustofluidic systems including acoustic wave generators for manipulating fluids, droplets, and micro/nano objects within a fluid suspension and related methods are disclosed herein. According to an aspect, an acoustofluidic system includes a substrate including a substrate surface. The system also includes an acoustic wave generator configured to generate acoustic streaming within an acoustic wave region of the substrate surface. Further, the acoustic wave generator is controllable to change the acoustic streaming for movement of a droplet or other micro/nano object on a fluid suspension about the acoustic wave region.

Abstract: Methods and devices for manipulating one or more particles (e.g., cells) in three dimensions using surface acoustic waves is described. Methods and devices for printing or more biological cells onto a substrate using surface acoustic waves are also provided.

Abstract: Apparatuses and methods for generating a chemical gradient within a flow channel include providing at least one bubble support structure within the flow channel. A bubble support structure helps maintain a bubble at a predetermined location in flow channel when a fluid flow passes therethrough. Oscillations are induced in the bubble using acoustic waves, which may be provided by a piezoelectric transducer located proximate the flow channel. Two or more inlets provide fluids of different chemical compositions into the flow channel, and bubble oscillations are used to generate a dynamically controllable mixing process.

Abstract: An apparatus for sorting cells from a mixed population of cells using surface acoustic waves is described. Methods for separating cancer cells from a mixed population of cells are provided. Methods for separating cells or particles having different size, density and/or compressibility properties are also provided.

Abstract: An apparatus for manipulating particles within a fluid sample includes a substrate having a substrate surface. A surface acoustic wave (SAW) generator generates a SAW within a SAW region of the substrate surface. The SAW has an SAW direction aligned with a pressure node. A channel is configured to receive the fluid sample and the fluid sample has a flow direction which is at an oblique angle to the SAW direction.

Abstract: An apparatus for manipulating particles uses tunable standing surface acoustic waves includes a channel defined on a substrate and a pair of variable frequency interdigital transducers. The channel is disposed asymmetrically between the transducers such that the zero order node location is outside of a working region in the channel.

Abstract: An acoustic manipulation process and acoustic manipulation device are disclosed. The acoustic manipulation process includes providing a device having a pathway positioned to receive a flow of a particle-containing fluid, transporting the particle-containing fluid into the pathway, and applying standing surface acoustic waves to the particle-containing fluid while the particle-containing fluid is flowing through the pathway. The applying of the standing surface acoustic waves to the particle-containing fluid includes nodes and anti-nodes of the standing surface acoustic waves extending through the particle-containing fluid. The acoustic manipulation device includes a pathway positioned to receive a flow of a particle-containing fluid, and a mechanism for generating and applying standing surface acoustic waves to the particle-containing fluid while the particle-containing fluid is flowing through the pathway.

Abstract: A microfluidic device comprises inlets for a sample flow and an out-of-plane focusing sheath flow, and a curved channel section configured to receive the sample flow and out-of-plane focusing sheath and to provide hydrodynamic focusing of the sample flow in an out-of-plane direction, the out-of-plane direction being normal to a plane including the curved channel. Examples of the invention also include improved flow cytometers.

Abstract: An acoustofluidic apparatus is provided that functions by the generation of microstreaming in fluid produced by the oscillation of oscillatory elements excited by an energy input such as acoustic energy. An acoustofluidic apparatus includes an oscillatory energy field generator in energetic contact with one or more oscillatory elements contained in a fluid passage. Oscillation of the oscillatory elements induces microstreaming in a fluid that can be used to mix laminar flows of differing fluids, as a micropump for the directional movement of fluid through a fluid passage, for the generation of waveforms in a fluid or plurality of fluids or for other purposes.

Abstract: Apparatuses and methods for generating a chemical gradient within a flow channel include providing at least one bubble support structure within the flow channel. A bubble support structure helps maintain a bubble at a predetermined location in flow channel when a fluid flow passes therethrough. Oscillations are induced in the bubble using acoustic waves, which may be provided by a piezoelectric transducer located proximate the flow channel. Two or more inlets provide fluids of different chemical compositions into the flow channel, and bubble oscillations are used to generate a dynamically controllable mixing process.

Abstract: An apparatus for manipulating particles within a fluid sample includes a substrate having a substrate surface. A surface acoustic wave (SAW) generator generates a SAW within a SAW region of the substrate surface. The SAW has an SAW direction aligned with a pressure node. A channel is configured to receive the fluid sample and the fluid sample has a flow direction which is at an oblique angle to the SAW direction.

Abstract: Examples of the present invention include apparatus and methods for particle focusing, for particles within a fluid sample. An example apparatus, which may be a microfluidic device, comprises a substrate, a channel receiving the fluid sample, and at least one surface acoustic wave (SAW) generator. The SAW generator may comprise electrodes supported by the substrate. In some examples, the channel has a particle focusing region located near a region of the substrate surface in which a SAW is generated. Particles are concentrated within one or more particle focus regions of the sample flow (the particle focus regions being appreciably narrower than the channel dimensions) by the effects of the SAW. As an example, a pair of SAW generators can be used to generate a standing surface acoustic wave (SSAW) that is used for particle focusing.

Abstract: A lens device includes a substrate having a channel and a first fluid flow path and a second fluid flow path. The first and second fluid flow paths at least partially in communication with the channel. A light emitting device is positioned adjacent to the channel. At least one first fluid source is in communication with the first fluid path such that a first fluid is moveable along the first fluid path and at least one second fluid source in communication with the second fluid path such that a second fluid is moveable along the second fluid path. The fluid paths are configured so the first fluid and second fluid move through the channel to define an adjustable liquid gradient refractive index distribution in the channel. Adjustment of the liquid gradient refractive index distribution permits a change of liquid lens focal distance or an angular adjustment of light.

Abstract: A lens device includes a substrate having a channel and a first fluid flow path and a second fluid flow path. The first and second fluid flow paths at least partially in communication with the channel. A light emitting device is positioned adjacent to the channel. At least one first fluid source is in communication with the first fluid path such that a first fluid is moveable along the first fluid path and at least one second fluid source in communication with the second fluid path such that a second fluid is moveable along the second fluid path. The first second fluid paths are configured so the first fluid and second fluid move through the channel to define an adjustable liquid gradient refractive index distribution in the channel. Adjustment of the liquid gradient refractive index distribution permits a change of liquid lens focal distance or an angular adjustment of light emitted by the light emitting device.

Abstract: A microfluidic device comprises inlets for a sample flow and an out-of-plane focusing sheath flow, and a curved channel section configured to receive the sample flow and out-of-plane focusing sheath and to provide hydrodynamic focusing of the sample flow in an out-of-plane direction, the out-of-plane direction being normal to a plane including the curved channel. Examples of the invention also include improved flow cytometers.

Abstract: A microfluidic device comprises inlets for a sample flow and an out-of-plane focusing sheath flow, and a curved channel section configured to receive the sample flow and out-of-plane focusing sheath and to provide hydrodynamic focusing of the sample flow in an out-of-plane direction, the out-of-plane direction being normal to a plane including the curved channel.