Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > A model system for group behavior of nanomachines

Abstract:
Probing for principles underlying flock patterns

A model system for group behavior of nanomachines

Germany | Posted on September 5th, 2010

For the casual observer it is fascinating to watch the orderly and seemingly choreographed motion of hundreds or even thousands of fish, birds or insects. However, the formation and the manifold motion patterns of such flocks raise numerous questions fundamental to the understanding of complex systems. A team of physicists from Technische Universitaet Muenchen (TUM) and LMU Muenchen has developed a versatile biophysical model system that opens the door to studying these phenomena and their underlying principles. Using a combination of an experimental platform and theoretical models, more complex systems can now be described and their properties investigated. The Munich researchers report on their findings in the current issue of the renowned journal Nature.

"Everything flows and nothing abides," is a saying ascribed to the Greek philosopher Heraclitus. Large groups of individuals may show collective behavior where the individuals' actions appear to be coordinated or even subordinated to the common good: Flocks of birds move through the air without a conductor, as if they were choreographed, and shoals of fish change their direction instantaneously when a shark appears. Yet science is still puzzled: Do all these systems obey the same universal laws? Does complex group behavior emerge from simple interactions between individuals intrinsically and inevitably? A team of researchers headed by Professor Andreas Bausch, Chair of Biophysics at TUM and Professor Erwin Frey, Chair of Statistical and Biological Physics at LMU, are unraveling the mystery.

The Munich researchers have developed a biophysical model system that makes it possible to carry out targeted high-precision experiments under controlled conditions. To this end, Volker Schaller from the TUM Chair of Biophysics, first author of the study, fixed biological motor proteins to a microscope coverslip in such a way that they could drive filaments of the muscle protein actin, suspended loosely over them, in any direction. The filaments measure about seven nanometers across, i.e. seven millionths of a meter, and are about ten micrometers long, i.e. a ten thousandth of a millimeter. The movement of the filaments is visualized using high-resolution microscopy.

In the experiments described in Nature, the actin filaments began to move as soon as ATP - the fuel for the motor proteins - was added. With low concentrations of actin filaments, the motion remained completely chaotic. Once the density crossed a threshold of five actin filaments per square micrometer, the filaments began to move collectively in larger clusters - with an astonishing resemblance to flocks of birds or shoals of fish. "We can set and observe all relevant parameters in this system," says Schaller. "Using this approach, we can experimentally test the propositions of different theories on self-organization - and that on the tiny scale of 'nanomachines'."

Structures like waves, swirls or ordered clusters seem to appear spontaneously during the experiments. Some of these structures grow to a size of almost one millimeter and remain stable for up to 45 minutes before they dissolve again. Based on these observations, Frey, together with his PhD student Christoph Weber, developed theoretical models to describe the experimental results. With the combination of extensible theoretical models and a precisely controllable experiment, the physicists have set out to tackle more difficult problems and unravel their underlying principles.

"Self-organization phenomena surround us on all levels of our lives," says Bausch. "It begins with traffic jams and the movement of human crowds or the swarming of animals and extends all the way to the organization of biological processes. Important examples are the formation of the cellular cytoskeleton or protein transport facilitated by motor proteins in cells." The underlying principles, though - whether in economic, biological or physical systems - are still among the great open questions of theoretical physics. "For our understanding of nature, as well, there are many fundamental principles yet to be discovered," emphasizes Frey. "However, forecasts should not be applied to the dynamics of human crowds over-hastily - thus far, their complexity is much too great to be captured in simple theoretical models."

The research is funded by the Deutsche Forschungsgemeinschaft (DFG, SFB 863), the cluster of excellence Nanosystems Initiative Munich (NIM), the TUM Institute for Advanced Study at the Technische Universitaet Muenchen, and the Elite Network of Bavaria (CompInt, NanoBioTechnology).

Original publication:

Volker Schaller, Christoph Weber, Christine Semmrich, Erwin Frey und Andreas R. Bausch: Polar patterns of driven filaments. Nature, 2 September 2010, pp 73-77 - doi:10.1038/nature09312

Video: Ordering of nanorods through collective motion of actively driven Filaments

e27.compint.de/index.php?id=214

####

For more information, please click here

Contacts:
Prof. Andreas Bausch
Technische Universitaet Muenchen
Chair of Biophysics (E 27)
James Franck Str. 1, 85748 Garching
Tel.: +49 89 / 289-12480
Fax: +49 89 / 289-14469

bio.ph.tum.de

Prof. Erwin Frey
Ludwig-Maxmilians-Universitaet Muenchen
Chair of Statistical and Biological Physics
Theresienstraße 37, 80333 Muenchen
Tel.: +49 89 / 2180-4537
Fax: +49 89 / 2180-4154

theorie.physik.uni-muenchen.de/lsfrey

Copyright © Technische Universitaet Muenchen

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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Govt.-Legislation/Regulation/Funding/Policy

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

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes 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

National Space Society Helps Fund Expanding Frontier’s Brownsville Summer Entrepreneur Academy: National Space Society and Club for the Future to Support Youth Development Program in South Texas June 24th, 2022

How a physicist aims to reduce the noise in quantum computing: NAU assistant professor Ryan Behunin received an NSF CAREER grant to study how to reduce the noise produced in the process of quantum computing, which will make it better and more practical April 1st, 2022

Molecular Machines

First electric nanomotor made from DNA material: Synthetic rotary motors at the nanoscale perform mechanical work July 22nd, 2022

Nanotech scientists create world's smallest origami bird March 17th, 2021

Controlling the speed of enzyme motors brings biomedical applications of nanorobots closer: Recent advances in this field have made micro- and nanomotors promising devices for solving many biomedical problems October 13th, 2020

Giant nanomachine aids the immune system: Theoretical chemistry August 28th, 2020

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

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project