Home > Press > UCLA bioengineers discover how particles self-assemble in flowing fluids
A self-assembled lattice of 10-micrometer diameter particles flowing through a microfluidic channel. |
Abstract:
Bioengineers at the UCLA Henry Samueli School of Engineering and Applied Science have been exploring a unique phenomenon whereby randomly dispersed microparticles self-assemble into a highly organized structure as they flow through microscale channels.
By Matthew Chin and Wileen Wong Kromhout
From atomic crystals to spiral galaxies, self-assembly is ubiquitous in nature. In biological processes, self-assembly at the molecular level is particularly prevalent.
Phospholipids, for example, will self-assemble into a bilayer to form a cell membrane, and actin, a protein that supports and shapes a cell's structure, continuously self-assembles and disassembles during cell movement.
Bioengineers at the UCLA Henry Samueli School of Engineering and Applied Science have been exploring a unique phenomenon whereby randomly dispersed microparticles self-assemble into a highly organized structure as they flow through microscale channels.
This self-assembly behavior was unexpected, the researchers said, for such a simple system containing only particles, fluid and a conduit through which these elements flow. The particles formed lattice-like structures due to a unique combination of hydrodynamic interactions.
The research, published online today in the journal Proceedings of the National Academy of Sciences, was led by UCLA postdoctoral scholar Wonhee Lee and UCLA assistant professor of bioengineering Dino Di Carlo.
The research team discovered the mechanism that leads to this self-assembly behavior through a series of careful experiments and numerical simulations. They found that continuous disturbance of the fluid induced by each flowing and rotating particle drives neighboring particles away, while migration of particles to localized streams due to the momentum of the fluid acts to stabilize the spacing between particles at a finite distance. In essence, the combination of repulsion and localization leads to an organized structure.
Once they understood the mechanism, the team developed microchannels that allowed for "tuning" of the spatial frequency of particles within an organized particle train. They found that by simply adding short regions of expanded channel width, the particles could be induced to self-assemble into different structures in a controllable and potentially programmable way.
"Programmable control of flowing microscale particles may be important in opening up new capabilities in biomedicine, materials synthesis and computation, similar to how improved control of flowing electrons has enabled a revolution in computing and communication," Di Carlo said.
For example, controlling the positions of microscale bioparticles, such as cells in flowing channels, is important for the operation of blood analysis and counting diagnostic systems. In addition, improving the uniformity of cell concentrations entering the microscale volume of a print head can enable burgeoning fields such as "tissue printing," in which single cells in a polymer ink are sequentially positioned to form a functional tissue architecture, such as the cylindrical lumen of a blood vessel.
More complete control of lattices of particles may also allow tunable manufacturing of optical or acoustic metamaterials that interact uniquely with light and sound waves based on the arrangement of the embedded particles, the researchers said.
####
About UCLA Henry Samueli School of Engineering and Applied Science
The UCLA Henry Samueli School of Engineering and Applied Science, established in 1945, offers 28 academic and professional degree programs and has an enrollment of almost 5,000 students. The school's distinguished faculty are leading research to address many of the critical challenges of the 21st century, including renewable energy, clean water, health care, wireless sensing and networking, and cyber-security. Ranked among the top 10 engineering schools at public universities nationwide, UCLA Engineering is home to seven multimillion-dollar interdisciplinary research centers in wireless sensor systems, nanoelectronics, nanomedicine, renewable energy, customized computing, and the smart grid, all funded by federal and private agencies.
For more information, please click here
Contacts:
Media Contacts
Matthew Chin
310-206-0680
Wileen Wong Kromhout
(310) 206-0540
Copyright © UCLA
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related News Press |
News and information
Researchers develop artificial building blocks of life March 8th, 2024
Possible Futures
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Academic/Education
Rice University launches Rice Synthetic Biology Institute to improve lives January 12th, 2024
Multi-institution, $4.6 million NSF grant to fund nanotechnology training September 9th, 2022
Self Assembly
Liquid crystal templated chiral nanomaterials October 14th, 2022
Nanoclusters self-organize into centimeter-scale hierarchical assemblies April 22nd, 2022
Atom by atom: building precise smaller nanoparticles with templates March 4th, 2022
Nanostructures get complex with electron equivalents: Nanoparticles of two different sizes break away from symmetrical designs January 14th, 2022
Nanomedicine
High-tech 'paint' could spare patients repeated surgeries March 8th, 2024
Researchers develop artificial building blocks of life March 8th, 2024
Discoveries
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
Researchers’ approach may protect quantum computers from attacks March 8th, 2024
High-tech 'paint' could spare patients repeated surgeries March 8th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Announcements
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Nanobiotechnology
High-tech 'paint' could spare patients repeated surgeries March 8th, 2024
Researchers develop artificial building blocks of life March 8th, 2024
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||