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.

Provided is a bubble volume control method and apparatus, and more particularly, to a bubble volume control method and apparatus for controlling the volume of a bubble by increasing or decreasing the volume of the bubble by emitting an ultrasonic wave having a resonance frequency corresponding to the size of the bubble located at the bottom of a container containing a liquid, such as water with bubbles composed of air, vapor, etc., toward the bubble by using an ultrasonic generator above the container, and maximizing a function of adjusting the volume of a bubble through a resonance effect by adjusting a liquid surface height of a liquid with the bubble according to a wavelength of an emitted ultrasonic wave.

Provided is a bubble volume control method and apparatus, and more particularly, to a bubble volume control method and apparatus for controlling the volume of a bubble by increasing or decreasing the volume of the bubble by emitting an ultrasonic wave having a resonance frequency corresponding to the size of the bubble located at the bottom of a container containing a liquid, such as water with bubbles composed of air, vapor, etc., toward the bubble by using an ultrasonic generator above the container, and maximizing a function of adjusting the volume of a bubble through a resonance effect by adjusting a liquid surface height of a liquid with the bubble according to a wavelength of an emitted ultrasonic wave.

Novel systems and methods are provided that rapidly separate particles from a liquid. In an embodiment, a small volume of liquid (such as a blood sample, or any other solution with a concentration of particles) is input into a flow device implemented as a unilateral channel. When activated by an acoustic energy source (such as an ultrasound pulse), gas-liquid interfaces naturally occurring between the liquid in the flow device and a plurality of gas-filled cavities that line the channel will oscillate and create stable cavitation streaming within a localized region of the surrounding liquid. These oscillations create micro-vortices that gently remove and trap particles and debris from the liquid and adjacent surfaces. Fluid and particle manipulation can thus be accomplished on a passive, disposable chip that is placed on top of an external acoustic transducer with a coupling medium.

Disclosed are methods and systems for implementing dynamic control of acoustic fields, which involves the use of machine learning through a Markov Decision Process. The machine learning algorithm monitors an attribute of a system and maintains the attribute within a range by altering a signal sent to an acoustic transducer. The acoustic transducer is configured to alter the attribute of the system. The attribute may be an attribute of the acoustic field produced by the acoustic transducer, or may be an attribute of another element of the system, such as a fluid, a rotor, or a cell mass.

In one embodiment, a microfluidic mixing device includes a mixing channel, a fluid inlet chamber to pass fluids into the mixing channel, an axis-asymmetric mixing actuator integrated within the channel to cause fluid displacements that mix the fluids as they flow through the channel, and an outlet chamber to receive the mixed fluids.

Disclosed is a centrifugal microfluidic device comprising a piezoelectric substrate; a rotatable platform device on the substrate; and at least one transducer on the substrate, the transducer being configured to generate a surface acoustic wave that propagates on the surface of the substrate and contacts the rotatable platform device asymmetrically to transfer energy thereto with a lateral distribution to cause rotation of the rotatable platform device. The device may be a microfluidic valve, a microfluidic mixer or a microfluidic particle concentrator.