Method and systems for microfluidic logic devices
Inventors
Devaraju, Naga Gopi • Unger, Marc A.
Assignees
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Publication Number
US-12220702-B2
Publication Date
2025-02-11
Expiration Date
Abstract
A microfluidic device includes an input source characterized by a source pressure, an input channel in fluid communication with the input source, and an output channel. The microfluidic device also includes a normally closed valve having a closed state and an open state. The normally closed valve is disposed between the input channel and the output channel. The microfluidic device further includes one or more release chambers coupled to a pressure source. Activation of the pressure source deforms the one or more release chambers, placing the normally closed valve in the open state.
Core Innovation
The invention provides a microfluidic device that implements pressure-actuated microfluidic logic using multilayer soft lithography and elastomeric polymers. The device includes an input source characterized by a source pressure, an input channel in fluid communication with the input source, and an output channel. A flow channel is positioned between the input channel and the output channel on a first side of a flow layer membrane.
A normally closed valve is implemented with a control channel separated from the flow channel by a control layer membrane. The normally closed valve has a closed state and an open state. One or more release chambers are coupled to a pressure source, and activation of the pressure source deforms the one or more release chambers to form an opening in the flow channel between the control layer membrane and the flow layer membrane, thereby placing the normally closed valve in the open state.
The invention further provides multilayer structures and materials for the valve, including a control layer, a flow layer, and a fill layer with a fill channel and a fill layer membrane. The fill layer includes a solid fill material configured to deflect the flow layer membrane toward the control layer so that portions of the membranes contact. This structure supports cascaded microfluidic logic devices, including logic gates such as NOT, NAND, and NOR, and supports higher-level functions including flip-flops, oscillators, delay or shift registers, and autonomous pumps.
Claims Coverage
The partial content provides one independent claim. It defines a pressure-actuated normally closed valve in a multilayer microfluidic device, where release chambers activated by a pressure source deform to create an opening in the flow channel and thereby switch the valve to an open state. The dependent claims refine the valve structure, layer materials, transition pressure constraints, and gate functionality.
Pressure-actuated normally closed valve with release chambers
A microfluidic device including an input channel and an output channel separated by a flow channel on a first side of a flow layer membrane, a normally closed valve with a control channel separated from the flow channel by a control layer membrane, and one or more release chambers coupled to a pressure source, wherein activation of the pressure source deforms the one or more release chambers to form an opening in the flow channel between the control layer membrane and the flow layer membrane, thereby placing the normally closed valve in the open state.
Layered membrane valve implementation with fill-induced membrane deflection
The normally closed valve includes a substrate with a control layer including a control channel and a control layer membrane, a flow layer including a flow channel and a flow layer membrane, and a fill layer including a fill channel and a fill layer membrane, wherein solid fill material deflects the flow layer membrane toward the control layer such that portions of the membranes contact.
PDMS membranes for control and fill layers
The control layer membrane and the fill layer membrane comprise PDMS.
Binary microfluidic logic gates including buffer, NOT, NOR, or NAND
The binary logic gates comprise at least one of buffer, NOT, NOR, or NAND gates.
Transition pressure greater than atmospheric pressure
The device further includes a second pressure source coupled to the normally closed valve to modify a transition pressure between the closed state and the open state to a value greater than atmospheric pressure.
Overall claim coverage centers on a microfluidic device with a normally closed valve formed by a control channel and a control layer membrane separated from a flow channel and a flow layer membrane. Release chambers activated by a pressure source open the valve by deforming to create an opening in the flow channel, and the valve is further supported by multilayer construction with a fill layer that deflects membranes. Dependent refinements specify membrane implementation details, transition pressure constraints, and binary logic gate types.
Stated Advantages
Enables pressure-actuated switching of a normally closed valve to an open state by activation of a pressure source.
Supports microfluidic logic operations through cascaded digital logic gates such as NOT, NAND, and NOR.
Supports higher-level circuit-like functions including flip-flops, oscillators, delay or shift registers, and autonomous pumps.
Implements a multilayer valve structure that uses solid fill material to deflect membranes and support membrane contact in the closed state.
Documented Applications
Microfluidic logic devices implementing digital logic gates including NOT, NAND, and NOR, with cascaded operation.
Higher-level microfluidic circuit-like functions including flip-flops, oscillators, delay flip-flops, and shift registers.
Autonomous pumps.
An integrated microfluidic system coupled to a microfluidic processing system, including workflow examples that include PCR.
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