Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > A drop of water as a model for the interplay of adhesion and stiction

The boron nitride nanomesh superhoneycomb: nitrogen (green), boron (orange), rhodium (grey); distance between honeycombs 3.2 nm.
CREDIT: Marcella Iannuzzi, UZH & Ari Seitsonen, ENS Paris
The boron nitride nanomesh superhoneycomb: nitrogen (green), boron (orange), rhodium (grey); distance between honeycombs 3.2 nm.

CREDIT: Marcella Iannuzzi, UZH & Ari Seitsonen, ENS Paris

Abstract:
How can a gecko move across a ceiling upside down? Two mechanisms are responsible: Adhesion via billions of extremely fine hairs on its feet, which enable it to stick to ceilings and walls. And as soon as the gecko moves, it relies on stiction. However, any change of adhesion and stiction at macroscopic level is expressed on the nanometer scale through the change in the forces exerted between atoms and molecules.

A drop of water as a model for the interplay of adhesion and stiction

Zurich, Switzerland | Posted on June 30th, 2016

How a drop of water touches a honeycomb structure

An international team of researchers headed by Thomas Greber from the University of Zurich's Physik-Institut succeeded in changing the manner in which a drop of liquid adheres to a surface by altering the electric voltage applied to a water drop. The surface upon which the drop lies consists of a material known as nanomesh, a single boron nitride layer on metallic rhodium. The structure is shaped like honeycomb with a comb depth of 0.1 nanometers and comb-comb distance of 3.2 nanometers.

Macroscopically, the change in electrical voltage is expressed in the change of the contact angle between the drop and the nanomesh surface. The contact or wetting angle refers to the angle that a drop of liquid assumes with respect to the surface of a solid. This angle can be measured with the aid of backlit photographs.

Change in the surface structure alters the contact angle of the drop

On the nanometer scale, the change in voltage causes the following: The nitrogen bonds with the rhodium are replaced by hydrogen-rhodium bonds, which flattens the nanomesh structure. How strongly the boron nitride's nitrogen binds to the surface of the rhodium depends on its distance from and direction to the next rhodium atom. And this determines the honeycomb structure and depth of the boron nitride layer. If the voltage changes, hydrogen accumulates between the boron nitride and the rhodium layer, which causes the honeycomb boron nitride layer to become flat. Tunneling microscopy can be used to detect this nanoscopic effect - the change in the surface properties of the nanomesh - in the liquid.

"To understand and control the interplay between the macro and the nano-world is the real challenge in nanoscience," stresses Greber. After all, six orders of magnitude need to be bridged - from millimeters in length (10-3 m) to nanometers (10-9 m); that's a factor of one million. "Our model system of the electrically switchable nanomesh and a drop's observable contact angle enables us to access the fundamental phenomenon of the friction of liquids on surfaces more precisely. This should help us solve problems that crop up during lubrication more effectively, for instance." The research project actually appears on the cover of the latest issue of the renowned journal Nature.

On the one hand, the new system is interesting for biology. Applying this effect should make it possible to control the adhesion and movement of cells. Aspects such as cell migration or the formation of complex, multicellular structures with new scientific approaches might be researched as a result. On the other hand, technological applications such as capillary pumps, where the capillary height can be controlled via electrical voltage, or micro-capillaries, where the flow resistance can be controlled, are also conceivable.

###

About the study

The research results were achieved within the scope of the Sinergia Program of the Swiss National Science Foundation (SNSF). The SNSF uses this instrument to promote the collaboration between several research groups, which conduct research across disciplines with the prospect of ground-breaking results. Besides the University of Zurich, the Katholieke Universiteit Leuven, Vienna University of Technology and Empa were also involved.

####

For more information, please click here

Contacts:
Thomas Greber

41-446-355-744

Copyright © University of Zurich

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 Links

RELATED JOURNAL ARTICLE:

Related News Press

News and information

Nanometrics to Announce Second Quarter Financial Results on July 30, 2019 July 17th, 2019

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

Physics

Strange warping geometry helps to push scientific boundaries July 12th, 2019

Spontaneous synchronisation achieved at the nanoscale July 4th, 2019

New study shows nanoscale pendulum coupling July 3rd, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Govt.-Legislation/Regulation/Funding/Policy

Caught in the act: Images capture molecular motions in real time July 15th, 2019

An 'EpiPen' for spinal cord injuries July 12th, 2019

The best of both worlds: how to solve real problems on modern quantum computers July 12th, 2019

What happens when you explode a chemical bond? Attosecond laser technique yields movies of chemical bond dissociation July 12th, 2019

Possible Futures

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

Dresden physicists use nanostructures to free photons for highly efficient white OLEDs: Trapped light particles July 12th, 2019

Strange warping geometry helps to push scientific boundaries July 12th, 2019

Nanomedicine

An 'EpiPen' for spinal cord injuries July 12th, 2019

Nanotechnology delivers hepatitis B vaccine: X-ray imaging shows that nanostructured silica acts as a protective vehicle to deliver intact antigen to the intestine so that it can trigger an immune response. The material can give rise to a polyvaccine against six diseases July 12th, 2019

Sheaths drive powerful new artificial muscles July 11th, 2019

Nanotechnology pioneer Chad Mirkin wins Kabiller Prize in Nanoscience and Nanomedicine: Molly Stevens of Imperial College London receives Kabiller Young Investigator Award July 11th, 2019

Discoveries

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

Strange warping geometry helps to push scientific boundaries July 12th, 2019

Announcements

Nanometrics to Announce Second Quarter Financial Results on July 30, 2019 July 17th, 2019

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

An 'EpiPen' for spinal cord injuries July 12th, 2019

Nanobiotechnology

An 'EpiPen' for spinal cord injuries July 12th, 2019

Nanotechnology delivers hepatitis B vaccine: X-ray imaging shows that nanostructured silica acts as a protective vehicle to deliver intact antigen to the intestine so that it can trigger an immune response. The material can give rise to a polyvaccine against six diseases July 12th, 2019

Nanotechnology pioneer Chad Mirkin wins Kabiller Prize in Nanoscience and Nanomedicine: Molly Stevens of Imperial College London receives Kabiller Young Investigator Award July 11th, 2019

Imprinted spheres fight breast cancer: Inhibition of HER2 on tumor cells by molecularly imprinted nanoparticles July 9th, 2019

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