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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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Ratcheting fluid pumps: Using generalized polynomial chaos expansions to assess pumping performance and sensitivity
A large diversity of fluid pumps is found throughout nature. The study of these pumps has provided insights into fundamental fluid dynamic processes and inspiration for the development of micro-fluid devices. Recent work by Thiria and Zhang [Appl. Phys. Lett. 106, 054106 (2015)] demonstrated how a reciprocal, valveless pump with a geometric asymmetry could drive net fluid flow due to an impedance mismatch when the fluid moves in different directions. Their pump's geometry is reminiscent of the asymmetries seen in the chains of contractile chambers that form the insect heart and mammalian lymphangions. Inspired by these similarities, we further explored the role of such geometric asymmetry in driving bulk flow in a preferred direction. We used an open-source implementation of the immersed boundary method to solve the fluid-structure interaction problem of a viscous fluid moving through a sawtooth channel whose walls move up and down with a reciprocal motion. Using a machine learning approach based on generalized polynomial chaos expansions, we fully described the model's behavior over the target 3-dimensional design space, composed of input Reynolds numbers (Rein), pumping frequencies, and duty cycles. Scaling studies showed that the pump is more effective at higher intermediate Rein. Moreover, greater volumetric flow rates were observed for near extremal duty cycles, with higher duty cycles (longer contraction and shorter expansion phases) resulting in the highest bulk flow rates.
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- PAR ID:
- 10616594
- Publisher / Repository:
- AIP Publishing
- Date Published:
- Journal Name:
- Physics of Fluids
- Volume:
- 36
- Issue:
- 12
- ISSN:
- 1070-6631
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1063/5.0237403
