Acoustophoretic Particle Separation Using Multi-Dimensional Standing Waves
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Solution Overview
Problem
Conventional acoustophoresis devices face limitations in scalability, fluid flow rates, and efficiency due to heat generation, use of planar standing waves, and inability to capture diverse materials, leading to suboptimal particle separation and collection processes.
Innovation Solution
The development of acoustophoretic systems with improved fluid dynamics using multi-dimensional acoustic standing waves, vertical flow paths, and optimized ultrasonic transducers with piezoelectric materials to create a ratio of lateral to axial radiation forces of the same order of magnitude, enhancing particle concentration and separation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical filtration process is used to separate particle clumps, then particles are separated from fluid, but filter capacity is reduced and periodic stopping is required
Solution Approach 1:
The invention extracts the harmful filtering action by removing particles through gravitational settling at the outlet rather than through physical filtration. The fluid exits the chamber without passing through filter media, eliminating filter capacity limitations and enabling continuous operation.
Solution Approach 2:
The invention replaces the mechanical filtration system with an acoustic field system. Acoustic standing waves aggregate particles into clumps that then settle gravitationally, substituting mechanical filter media with a combination of acoustic and gravitational forces for continuous separation.
2Reliability
If diatomaceous earth filter is used in bioreactor filtration, then cells and debris are separated, but flux rate decreases and pressure differential increases
Solution Approach 1:
The invention extracts particles from the fluid stream through gravitational settling at the outlet rather than forcing fluid through filter media. This eliminates the flux rate limitation and pressure differential problems associated with DE filters while maintaining separation efficiency.
Solution Approach 2:
The invention uses acoustic waves (a form of fluid dynamics) to aggregate particles, which then settle under gravity. This fluid-based approach replaces the solid filter media approach, enabling high flux rates without pressure differential limitations.
3Reliability
If physical filter media is used, then particles are trapped, but yield is reduced due to product loss in filter saturation
Solution Approach 1:
The invention extracts particles through gravitational settling at the outlet rather than trapping them in filter media. This eliminates product loss associated with filter saturation while maintaining effective particle removal, thereby preserving yield.
4Manufacturing precision
If conventional acoustophoresis systems operate at high frequency, then small particles are trapped, but scalability is limited and flow rates are very slow
Solution Approach 1:
The invention transitions from two-dimensional planar acoustic fields to three-dimensional acoustic standing wave fields with vertical particle transport. This dimensional change enables gravitational settling to act on aggregated particles, dramatically increasing flow rates while maintaining trapping capability.
Solution Approach 2:
The invention changes the operational parameters by using lower frequency acoustic waves that generate larger particle clumps suitable for gravitational settling, rather than high frequency waves that trap small particles but limit flow rate. This parameter change enables scalability and high productivity.
5Reliability
If planar acoustic standing waves are used, then particles are trapped, but continuous operation is not possible and power heating occurs
Solution Approach 1:
The invention adds the vertical dimension to particle transport, allowing particles to settle out of the acoustic field at the outlet. This enables continuous operation as particles are continuously removed rather than accumulated, and reduces power heating by eliminating the need to maintain high-intensity planar standing waves.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These systems enable continuous, high-flowrate particle separation with reduced drag and increased collection efficiency, minimizing waste and product loss in applications like bioreactor filtration, while maintaining the integrity of monoclonal antibodies and recombinant proteins.
Implementation Method 1
Acoustophoresis is the separation of particles and secondary fluids from a primary or host fluid using high intensity acoustic standing waves
Implementation Method 2
high intensity standing waves of sound can exert forces on particles in a fluid
Implementation Method 3
at least one ultrasonic transducer located on the sidewall of the acoustic chamber... the transducer including a piezoelectric material
Implementation Method 4
the pressure profile in a standing wave contains areas of local minimum pressure amplitudes at its nodes and local maxima at its anti-nodes. Depending on the density and compressibility of the particles, they will be trapped at the nodes or anti-nodes
Data Source
AI summary
Devices for separating materials from a host fluid are disclosed. The devices include an acoustic chamber having an inlet and an outlet. An ultrasonic transducer and reflector create a multi-dimensional acoustic standing wave in the acoustic chamber that traps the materials and permits a continuous separation of the materials from the host fluid. The materials and the host fluid can thus be separately collected. Multiple sets of trapping lines are generated by the acoustic standing wave, and the transducer is oriented to minimize cross-sectional area for straight vertical channels between the trapping lines.