Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Self-Stretching Material Developed at University of Rochester

17.02.2015

No limit to number of times material can change shape

Although most materials slightly expand when heated, there is a new class of rubber-like material that not only self-stretches upon cooling; it reverts back to its original shape when heated, all without physical manipulation.

The findings were recently published in the journal ACS Macro Letters.

The material is like a shape-memory polymer because it can be switched between two different shapes. “However, unlike other shape-memory polymers, the material does not need to be programmed each cycle—it repeatedly switches shapes, with no external forces, simply upon cooling and heating,” said Mitchell Anthamatten, an associate professor of chemical engineering.

Anthamatten and his team built on the success of a recently developed polymer that can also stretch when cooled. The other polymers need to have small loads—or weights—attached in order to direct the shape to be taken. That is not the case with the Rochester polymer, because Anthamatten’s team “tricked it into thinking” a load was attached.

To carry out their strategy, the researchers introduced permanent stress inside the material. They began with polymer strands that were loosely connected by bonds called crosslinks that create a network of molecules. The material was stretched with a load attached to give it the desired shape. At that point, they added more crosslinks and cooled the polymer, causing crystallization to occur along a preferred direction.

Anthamatten’s team showed that internal crystallization forces are strong enough to stretch the material along one direction. Once cooled below about 50 °C, polymer chain segments pack into highly ordered micro-layers called lamellae. This reorganization occurs within a network of polymer chains, causing the material’s length to increase by over 15 percent.

“The stress we built into the network takes the place of the load and enables the material to ‘remember’ the shape it will assume when it’s later cooled without a load,” said Anthamatten.

Conventional shape-memory polymers need to be reprogrammed after each cycle, but that’s not the case with the material developed by Anthamatten and his team. After multiple cycles of cooling and heating, they found that the material assumed its programmed shape and returned to its initial state with no noticeable deviation.

Anthamatten envisions the material being applied to a number of areas in which reversible shape-changes are needed during operations, including biotechnology, artificial muscles, and robotics.

“The next step is to optimize the shape of the polymer material and the energy released during the process,” said Anthamatten. “That will be done by adjusting the type and density of crosslinks that tie the individual chains together.”

The research team included two of Anthamatten’s students—Yuan Meng and Jisu Jiang. The work was supported internally by the University of Rochester’s Pump Primer Seed Grant Program, which exists to support proof-of-concept studies.

Contact Information
Peter Iglinski
Senior Press Officer, Science & Public Media
peter.iglinski@rochester.edu
Phone: 585-273-4726
Mobile: 585-764-7002

Peter Iglinski | newswise
Further information:
http://www.rochester.edu/news/

More articles from Materials Sciences:

nachricht New pop-up strategy inspired by cuts, not folds
27.02.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht Let it glow
27.02.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>