Related Experiment Video
Updated: Jan 21, 2026
11:08
Generation of Size-controlled Poly ethylene Glycol Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices
Published on: July 3, 2018
8.2K
Asynchronous generation of oil droplets using a microfluidic flow focusing system
Peter Thurgood1, Sara Baratchi2, Aram Arash3
1School of Engineering, RMIT University, Melbourne, Australia. Peter.thurgood@rmit.edu.au.
Scientific Reports
|July 24, 2019
Summary
Long-term water exposure reverses polydimethylsiloxane (PDMS) microfluidic systems, enabling oil-in-water droplet generation. This surface property change is reversible, offering dynamic control over droplet characteristics without special treatments.
Area of Science:
- Microfluidics
- Materials Science
- Surface Chemistry
Background:
- Polydimethylsiloxane (PDMS) is widely used in microfluidic devices.
- PDMS-based systems commonly generate water-in-oil droplets.
- Surface properties of PDMS can be altered by environmental exposure.
Purpose of the Study:
- To investigate the effect of long-term water exposure on PDMS microfluidic droplet generation.
- To characterize the resulting oil-in-water droplet generation.
- To explore methods for dynamic control and reversal of these surface changes.
Main Methods:
- Utilizing PDMS-based microfluidic droplet generation systems.
- Exposing systems to water for extended periods.
- Varying oil and water pressures, oil viscosities, and immiscible liquid combinations.
- Employing syringe pumps and a latex balloon pressure pump for dynamic control.
Main Results:
- Long-term water exposure reversed PDMS wettability, leading to oil-in-water droplet generation.
- Identified various droplet generation modes and studied droplet size, gap, and generation rate.
- Demonstrated dynamic control of droplet gap from hundreds of microns to a few microns.
- Reversal of surface properties achieved by exposing PDMS to ambient air.
Conclusions:
- PDMS microfluidic systems can be controllably reversed to generate oil-in-water droplets.
- Dynamic control of droplet spacing is achievable without complex equipment or treatments.
- Surface property modulation via environmental exposure offers a versatile approach for microfluidic applications.
Related Concept Videos
01:25Design Example: Flow of Oil Through Circular Pipes
459
Understanding fluid flow behavior through pipes is critical in fluid mechanics, especially in applications like oil transportation through pipelines. Hagen-Poiseuille's law provides an exact solution derived from the Navier-Stokes equations for steady, incompressible, and laminar flow within a circular pipe. Hagen-Poiseuille's law helps determine the necessary pressure drop across a pipeline section by determining parameters like pipe length, radius, oil viscosity, and the desired volumetric...
459
01:16Focusing of Light in the Eye
5.5K
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
5.5K
01:27Coping Strategies: Problem Focused
445
Coping strategies are methods people use to manage, tolerate, or reduce the effects of stressors. These strategies involve both behavioral and psychological actions to handle stressful situations. One common approach is problem-focused coping, which aims to change or eliminate the source of stress rather than merely addressing its consequences. This method involves taking direct action to resolve the issue causing stress.
For example, consider a student who struggles to understand their...
For example, consider a student who struggles to understand their...
445
01:20Coping Strategies: Emotion Focused
456
Emotion-focused coping refers to a set of strategies aimed at managing the emotional impact of stressors, rather than directly addressing their causes. This approach involves altering one's emotional response to stressful situations to reduce their psychological effects. For example, individuals might talk with a friend or engage in activities like journaling to express their feelings. Such actions can help achieve emotional clarity or release, providing the psychological stability needed...
456
01:26Methods of Documentation IV: Focus Charting
1.7K
Focus Charting, also known as the focus charting system or "focus documentation," is a systematic documentation approach used in healthcare to organize patient information in medical records.
It typically involves three columns for recording information:
It typically involves three columns for recording information:
1.7K
02:39Gene Flow
37.5K
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.
37.5K