Graphene, interrupted

One of the biggest challenges in working with a material whose chemical-binding properties are contingent upon physical construction is getting that material to "stay put" in its physical form long enough to get the material to do its chemical thing.

crinkled graphene

Graphene's physical construction is often likened to chicken wire, one atom thick; but when it is "unrolled" it can easily contract and constrict in upon itself,  "crumpling" like the skin of a grape into a raisin that has been left in the heat and sun too long.    In its crumpled form, graphene behaves differently, and is significantly more difficult to handle.  

But new research by Duke University offers a new technique for getting the graphene to un-crumple itself.   By adhering the graphene to a rubber film, the chicken wire lattice's crumpling can be controlled and flexed on demand: 

"Duke engineers attached the graphene on a rubber film that had been pre-stretched multiple times of its original size. Once the pre-stretch in the rubber film was relaxed, part of the graphene detached from the rubber while other part kept adhering on the rubber, forming an attached-detached pattern with a size of a few nanometers. As the rubber was relaxed, the detached graphene was compressed to crumple. Once the rubber film was stretched back, the adhered graphene will pull on the crumpled graphene to unfold it."  source: http://www.sciencedaily.com/releases/2013/01/130123165042.htm

This process opens up new frontiers for application such as artificial muscle, which needs a large surface area that can be "deformed" as the muscles constrict and relax naturally.

Xuanhe Zhao, one of the engineers researching this application said, "In particular, they promise to greatly improve the quality of life for millions of disabled people by providing affordable devices such as lightweight prostheses and full-page Braille displays. The broad impact of new artificial muscles is potentially analogous to the impact of piezoelectric materials on the global society."