Adhesion disturbed by noise

December 17, 2012
Adhesion disturbed by noise

Imagine a solid ball rolling down a slightly inclined ramp. What could be perceived as child's play is the focus of serious theoretical research by Manoj Chaudhury and Partho Goohpattader, two physicists from Lehigh University, Bethlehem, Pensylvania, USA. Their study, which is about to be published in European Physical Journal E, has one thing in common with childhood behaviour. It introduces a mischievous idea, namely studying the effect of random noise, such as vibrations, on the ball. They found it could lower the energy barrier to set the ball in motion.

The authors used a ramp with a micro-textured surface. This surface is akin to that of a gecko's feet, made of so-called microfibrils capable of adhering to any surface by deforming elastically. They then studied the effect of vibration on a ball left on the top of such a textured ramp. They found that the sphere starts rolling when subjected to a computer-generated random vibration.

To set the ball in motion requires activation energy, the model shows. It has been long known that the same applies to the adhesion of molecules, on a much smaller scale, as predicted theoretically by the so-called Arrhenius kinetics. This study pinpoints a finite threshold of intensity for the vibration noise above which the ball is set in motion.

This finding could have implications for the removal of from super- such as plant leaves. Other applications could also include gecko feet-mimetic adhesives, better adhesion of rubber tires on roads, and the use of fluids, instead of electronics, to perform a digital operation. In addition, new (MEMs), based on robotic fingers capable of displacing a small object, could be assisted by noise.

Explore further: Probing Question: How do dimples make golf balls travel farther?

More information: M. K. Chaudhury and P. S. Goohpattader (2012), Noise activated dissociation of soft elastic contacts, European Physical Journal E 35: 131, DOI: 10.1140/epje/i2012-12131-9

Related Stories

Air pressure matters when landing on sandy planets

July 3, 2007

A steel ball dropped into loose, fine sand makes an impressive splash, according to physicists of the Physics of Fluids group investigating the fluid-like properties of sand at the University of Twente in the Netherlands. ...

Dung beetle dance provides crucial navigation cues

January 18, 2012

( -- The dung beetle dance, performed as the dung beetle moves away from the dung pile with his precious dung ball, is a mechanism to maintain the desired straight-line departure from the pile, according to a ...

Scientists make animated collisions sounds realistic

August 21, 2012

( -- Bang. Clatter. Tinkle. Jingle. When solid objects collide in the real world we hear a sharp impact sound, sometimes followed by a ringing aftershock. Creating sounds like that to accompany computer animation ...

Recommended for you

CERN collides heavy nuclei at new record high energy

November 25, 2015

The world's most powerful accelerator, the 27 km long Large Hadron Collider (LHC) operating at CERN in Geneva established collisions between lead nuclei, this morning, at the highest energies ever. The LHC has been colliding ...

Exploring the physics of a chocolate fountain

November 24, 2015

A mathematics student has worked out the secrets of how chocolate behaves in a chocolate fountain, answering the age-old question of why the falling 'curtain' of chocolate surprisingly pulls inwards rather than going straight ...

'Material universe' yields surprising new particle

November 25, 2015

An international team of researchers has predicted the existence of a new type of particle called the type-II Weyl fermion in metallic materials. When subjected to a magnetic field, the materials containing the particle act ...

Biomedical imaging at one-thousandth the cost

November 23, 2015

MIT researchers have developed a biomedical imaging system that could ultimately replace a $100,000 piece of a lab equipment with components that cost just hundreds of dollars.


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (4) Dec 17, 2012
They found it could lower the energy barrier to set the ball in motion.
Everyone knows, that the vibrations reduce friction. The vibrating washing machine can slide across the whole room. How they could "find" it, after then?
2.5 / 5 (6) Dec 17, 2012
The vibrating washing machine can slide across the whole room. How they could "find" it, after then?

If it was still plugged in they probably followed the cord. If it had worked loose then maybe they followed the scuff marks on the floor.

Of course this is constrained by the absence of of lateral-transverse-longitudinal water standing waves in the washing machine.
1 / 5 (2) Dec 17, 2012
coefficients of static vs. kinetic friction?
not rated yet Dec 18, 2012
The Lunar Reconnaissance Orbiter circling the moon will pass over the mountain and attempt to photograph the skid marks left by the washing machine sized-spacecraft as they hit the surface at 3,800 mph.

There you go.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.