Thread-Driven Piston Mechanism for Precise Microfluidic Flow Control
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Solution Overview
Problem
Existing fluid control mechanisms in micro or small fluid channel systems face challenges in efficiently and conveniently controlling fluid motion due to difficulties in constructing precise valves and the complexity of syringe pump operations, which hinder automated fluid injection.
Innovation Solution
A fluid control mechanism with a chamber, chamber wall, and a movable piston that blocks or allows communication with fluid channels by moving to cover openings at the chamber's bottom, utilizing a piston motion control member with screw threads to manage fluid flow, and optionally incorporating a piston rod or elastic support for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If syringe pump is used for fluid injection, then fluid can be injected into the carrier, but the operation involves many steps and the microfluid sample is difficult to switch
Solution Approach 1:
The patent integrates the power source function directly into the carrier structure by forming a cavity within the carrier body that accommodates the piston mechanism. This merging of the power source and carrier into a single integrated structure eliminates the need for separate syringe pump operations, reducing operational steps while maintaining fluid injection capability.
Solution Approach 2:
The piston mechanism is designed to be movable within the carrier's cavity, allowing the carrier itself to perform the fluid propulsion function. The carrier structure includes components that enable the piston to move and push fluid directly, making the system self-sufficient without requiring external syringe pump operation.
2Ease of operation
If valves are constructed inside the carrier, then fluid motion can be controlled, but it is rather difficult to construct a sufficient number of valves that are easy to open and close with sufficient precision
Solution Approach 1:
Instead of constructing traditional valves that open and close within the carrier, the patent inverts the approach by using a movable piston that actively pushes fluid through the carrier's fluid channel. The piston's movement along the channel serves the valve function by controlling fluid flow direction and timing, eliminating the need for complex in-carrier valve construction.
Solution Approach 2:
The piston mechanism serves multiple functions: it acts as both the power source for fluid propulsion and the flow control mechanism. By moving the piston to different positions within the carrier's cavity, the system achieves both fluid injection and flow direction control, replacing the need for separate valves.
3Reliability
If piston moves to bottom portion of chamber to cover opening, then communication between chamber and fluid channel is blocked, but precise positioning is required
Solution Approach 1:
The piston is designed with a flexible membrane structure that can deform to seal against the opening at the bottom of the chamber. This flexible membrane design allows reliable fluid communication control through elastic deformation rather than requiring extremely precise rigid positioning, accommodating manufacturing tolerances while maintaining sealing effectiveness.
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
Enables precise control of fluid communication and flow in microfluidic systems, allowing automated fluid injection and improved efficiency in managing fluid channels with millimeter to micron-scale dimensions.
Implementation Method 1
a piston motion control member provided with external threads forming a screw thread pair with internal threads on the chamber wall, and configured to rotate along the threads to move in the chamber for driving the piston to move in the chamber
Implementation Method 2
a piston rod or elastic support for sealing
Data Source
AI summary
A fluid control mechanism includes a chamber, a chamber wall, a piston provided within the chamber, and at least one fluid channel. A bottom portion of the chamber is configured to be in communication with the fluid channel. An opening connecting the fluid channel and the chamber is arranged at the bottom portion of the chamber. A piston mechanism has a chamber and a chamber wall, and a piston and a piston motion control member provided within the chamber. The piston motion control member is provided with external threads forming a screw thread pair with internal threads on the chamber wall, and is configured to rotate along the threads to move within the chamber for driving the piston to move in the chamber. The piston mechanism and the fluid control device can accurately control liquid in a micro or small fluid channel system.