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Abstract An open-source pneumatic pressure pump is engineered for driving fluid flow in a microfluidic device. It is designed to be a cost-effective and customizable alternative to commercial systems. The pneumatic pressure pump utilizes a single open-source microcontroller to control four dual-valve pressure regulators. The control scheme is written in the Arduino development environment and the user interface is written in Python. The pump was used to pressurize water and a fluorinated oil that have similar viscosities. The pump can accurately control pressures to a resolution of less than 0.02 psig with rapid response times of less than one second, overshoot of desired pressures by less than 30%, and setting response times of less than two seconds. The pump was also validated in its ability to produce water-in-oil drops using a drop-making microfluidic device. The resultant drop size scaled as expected with the pressures applied to the emulsion phases. The pump is the first custom-made dual-valve regulator that is used to precisely control fluid flow in a microfluidic device. The presented design is an advancement towards making more fully open-source pneumatic pressure pumps for controlling flow in microfluidic devices.
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An embedded microfluidic valve for dynamic control of cellular communication
The communication between different cell populations is an important aspect of many natural phenomena that can be studied with microfluidics. Using microfluidic valves, these complex interactions can be studied with a higher level of control by placing a valve between physically separated populations. However, most current valve designs do not display the properties necessary for this type of system, such as providing variable flow rate when embedded inside a microfluidic device. While some valves have been shown to have such tunable behavior, they have not been used for dynamic, real-time outputs. We present an electric solenoid valve that can be fabricated completely outside of a cleanroom and placed into any microfluidic device to offer control of dynamic fluid flow rates and profiles. After characterizing the behavior of this valve under controlled test conditions, we developed a regression model to determine the required input electrical signal to provide the solenoid the ability to create a desired flow profile. With this model, we demonstrated that the valve could be controlled to replicate a desired, time-varying pattern for the interface position of a co-laminar fluid stream. Our approach can be performed by other investigators with their microfluidic devices to produce predictable, dynamic fluidic behavior. In addition to modulating fluid flows, this work will be impactful for controlling cellular communication between distinct populations or even chemical reactions occurring in microfluidic channels.
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- Award ID(s):
- 1946456
- PAR ID:
- 10516252
- Publisher / Repository:
- Applied Physics Letters
- Date Published:
- Journal Name:
- Applied physics letters
- Volume:
- 123
- Issue:
- 24
- ISSN:
- 1520-8842
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1063/5.0172538
