Dispensing Device Pressure-Gravity Flow Switching
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Solution Overview
Problem
Dispensing devices using pumps often mix liquid and gas phases at the nozzle tip, leading to splatters and bubbles, contaminating surrounding areas, especially in applications like cell culture where continuous discharge is not maintained, causing contamination at the start and end of dispensing.
Innovation Solution
A dispensing device with a syringe, a first pump for pressure-driven discharge, and a control unit that uses a second suction pump and valves to manage gas expulsion and liquid flow, allowing for initial pressure-driven discharge followed by free-fall discharge to minimize splatters and bubbles, ensuring precise targeting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a pump is used to discharge liquid, then the liquid can be dispensed continuously, but liquid and gas phases are easily mixed at the nozzle tip causing splatter and bubbles
Solution Approach 1:
The patent segments the dispensing process into distinct phases: a first discharge phase using pump pressure to maintain continuous flow, and a second discharge phase where the syringe moves to allow gravity-driven flow. This segmentation separates the continuous flow requirement from the splatter prevention requirement, as the syringe movement in the second phase prevents liquid-gas mixing at the nozzle tip while still maintaining dispensing continuity
Solution Approach 2:
The patent introduces dynamic movement of the syringe between two positions during the dispensing process. The syringe moves from a first position during pump-driven discharge to a second position during gravity-driven discharge. This dynamic positioning allows the system to maintain continuous liquid flow while preventing splatter and bubble generation at different stages of the dispensing cycle
2Adaptability or versatility
If the syringe is moved during dispensing, then liquid can be delivered to different locations, but bubbles may drip and contaminate the surroundings
Solution Approach 1:
The patent performs preliminary actions by completing the pump-driven discharge phase before initiating syringe movement for repositioning. The control unit is configured to execute the first discharge phase fully, then transition to the second discharge phase with syringe movement. This preliminary completion of pressure-driven discharge ensures that liquid-gas mixing is minimized before the syringe moves, preventing bubble dripping and contamination during the positioning phase
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
The solution effectively suppresses droplet and bubble generation at the end of dispensing, preventing contamination of the surroundings by utilizing a combination of pressure-driven and free-fall discharge mechanisms, ensuring accurate and clean liquid delivery.
Implementation Method 1
a first pump configured to generate pressure for discharging liquid in the syringe through the nozzle
Implementation Method 2
causing the liquid in the syringe to flow out due to its own weight
Data Source
AI summary
A dispensing device includes: a syringe including a nozzle; a first pump configured to generate a pressure to discharge a liquid in the syringe through the nozzle; and a control unit configured to, when discharging the liquid in the syringe, discharge a part of the liquid in the syringe with the pressure generated by the first pump and then cause the liquid in the syringe to run out under its own weight.