Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



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

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

Physics

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

Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024

Scientists use heat to create transformations between skyrmions and antiskyrmions January 12th, 2024

Focused ion beam technology: A single tool for a wide range of applications January 12th, 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

Possible Futures

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

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

Nanomedicine

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Researchers develop artificial building blocks of life 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

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

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

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

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

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

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