Aug 02, 2023

Public workspaceAutomatic flow in fluid-walled dumbbells driven by Laplace pressure

DOI
dx.doi.org/10.17504/protocols.io.bp2l695m5lqe/v1
  • 1Oxford Parkinson's Disease Centre and Department of Physiology, Anatomy and Genetics, University of Oxford, South Park Road, Oxford OX1 3QU, United Kingdom;
  • 2Kavli Institute for Neuroscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Park Road, Oxford OX1 3QU, United Kingdom;
  • 3Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815, USA;
  • 4Osney Thermofluids Institute, Department of Engineering Science, University of Oxford, Osney Mead, Oxford OX2 0ES, United Kingdom;
  • 5The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom.
Cláudia C. Mendes
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DOI: dx.doi.org/10.17504/protocols.io.bp2l695m5lqe/v1
Protocol Citation: Quyen Do, Federico Nebuloni, Richard Wade-Martins 2023. Automatic flow in fluid-walled dumbbells driven by Laplace pressure. protocols.io https://dx.doi.org/10.17504/protocols.io.bp2l695m5lqe/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: April 24, 2023
Last Modified: August 02, 2023
Protocol Integer ID: 80972
Keywords: Laplace pressure, automatic flow, dumbbell circuits, fluid-walled microfluidics
Funders Acknowledgement:
Aligning Science Across Parkinson’s (ASAP)
Grant ID: ASAP-020370
Abstract
This protocol describes experiments performed to quantify pressure and volume variations inside fluid-walled dumbbells when a pressure difference is generated between the two chambers. Difference in Laplace pressure automatically flows medium from the high-pressure chamber to the low pressure one. Flow stops when pressures are equilibrated.
Materials
Reagents:

Note
The fluorocarbon used as overlay and jet is a processed version of the FC40 listed in the reagents table and it is called FC40star. Process to make FC40star is property of and patented by iotaSciences Ltd. Every time in the protocol we refer to FC40 it implies FC40star.

Equipment:



Jet-Printing of Fluid-Walled Dumbbells
Jet-Printing of Fluid-Walled Dumbbells
Fill a virgin uniwell plate with 5 ml of DMEM supplemented with 10% FBS. Agitate the plate to spread the 5 mL of medium to cover the whole area of the plate.
Remove the volume leaving a thin layer of medium wetting the plate.
Gently overlay FC40 (~50 mL) pouring it in one of the corners.

Place the plate in the 3D traverse. Adjust x, y, z positions of the traverse head to coincide with the starting point of the movement path.
Start the pump, setting a constant flow at 480 μL/min.
Wait ~10 s to allow flow to be fully developed.
Start traverse automatic movement.
Note
Traverse movements are controlled by scripts written in G-code.

At completion of the movement path, stop pump and remove plate from the traverse.
Note
The 3D traverse consists of 3 orthogonal screws that allow head movement along Cartesian axes. Traverse moving head holds a blunt needle (inner diameter = 70 um) connected to an external syringe pump through a Teflon tube. The syringe on the pump and the whole tubing/needle is prefilled with FC40.

Establishment of Pressure Difference and Volumes Variation Measurements
Establishment of Pressure Difference and Volumes Variation Measurements
Place the newly printed plate into the pendant drop tensiometry machine.
Add FC40 to almost fill the plate entirely (~20 mL).
By mean of a syringe pump connected to a needle through a Teflon tube, infuse 4 μL in the right chamber and soon after 1 μL in the left chamber (infusion rate set on pump = 20 μl/min).
Record chambers height for 24 hours imaging every 30 minutes.