Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Team explains 'the wallpaper problem'

01.04.2008
Work could have industrial applications

Frustrated by tape that won't peel off the roll in a straight line? Angry at wallpaper that refuses to tear neatly off the wall?

A new study reveals why these efforts can be so aggravating. Wallpaper is not out to foil you-it's just obeying the laws of physics, according to a team of researchers from the Centre National de la Recherche Scientifique (CNRS) in Paris, the Universidad de Santiago, Chile, and MIT.

The report, published in the March 30 online issue of Nature Materials, sheds light on a phenomenon many people have experienced, which the researchers dubbed “the wallpaper problem.”

“You want to redecorate your bedroom, so you yank down the wallpaper. You wish that the flap would tear all the way down to the floor, but it comes together in a triangle and you have to start all over again,” said Pedro Reis, one of the authors of the paper and an applied mathematics instructor at MIT.

This pattern, where two cracks propagate toward each other and meet at a point, is extremely robust. It applies not only to wallpaper but other adhesives such as tape, as well as nonadhesive plastic sheets such as the shrink-wrap that envelops compact discs. It even extends to fruit: The skin on a tomato or a grape typically forms a triangle when peeled off.

“This has happened to everyone. it's frustrating,” said Reis, who collaborated with Enrique Cerda and Eugenio Hamm of the Universidad de Santiago, Benoit Roman of CNRS and Michael LeBlanc of the University of Chicago.

The team found that those ubiquitous triangular tears arise from interactions between three inherent properties of adhesive materials: elasticity (stiffness), adhesive energy (how strongly the adhesive sticks to a surface) and fracture energy (how tough it is to rip).

The researchers developed a formulation that predicts the angle of the triangle formed, based on those three properties.

They also figured out just how those triangular tears arise. As the strip is pulled, energy builds up in the fold that forms where the tape is peeling from the surface. The tape can release that energy in two ways: by unpeeling from its surface and by becoming narrower, both of which it does.

In a possible industrial application, materials engineers could use this method to calculate one of the three key properties, if the other two are known. This could be particularly useful in microtechnologies, such as stretchable electronics, where the characterization of thin material properties is very difficult.

Reis, who now works in MIT's Applied Mathematics Laboratory, and his collaborators at CNRS and Universidad de Santiago got the idea for the project after noticing consistent tearing patterns in plastic sheets such as the plastic wrapping of CDs.

The researchers tried controlled experimental versions of the same process in their lab and got the same results. “This shape is really robust, so there must be something fundamental going on that gives rise to these shapes,” Reis said.

However, the shapes formed by tearing nonadhesive sheets proved difficult to study because they are not perfect triangles, and without adhesion, the physics of the problem is more complicated. Instead, the researchers turned their attention to adhesives, which do form perfect triangles when torn.

The triangular shapes can also be seen in the work of French artist Jacques Villeglé. His art consists of posters taken from the streets of Paris and other French cities, complete with the same sort of rips that the researchers studied. One of the posters may be featured on the cover of Nature Materials to illustrate the team's paper.

Torn posters, tape and tomato skins may seem like strange research topics for physicists and applied mathematicians, but it's perfectly normal to Reis and his colleagues, who draw inspiration from an array of everyday objects.

Such real-world applications are not only fun to study, but “we can really learn things that will be useful for industry and help us understand the everyday world around us. It is also a great way to motivate students to be interested in science,” Reis said.

Elizabeth Thomson | alfa
Further information:
http://www.mit.edu

More articles from Studies and Analyses:

nachricht Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>