Researchers from Hyderabad, India, present the first ever documented observation of the self-healing phenomena of graphene. This discovery may have potential for use in artificial skin.
Graphene is a sheet of pure carbon atoms, and currently the strongest material in the world. It is one million times thinner than paper; so thin that it is in fact considered two dimensional. Graphene has rapidly become a comer among the most prospective nanomaterials because of its unique properties and versatile potential applications.
The research paper published in Open Physics refers to an astonishing yet formerly undocumented self-healing property of graphene, which could pave the way to the development of flexible sensors that imitate the self-healing properties of human skin.
The skin being the largest organ in the human body possesses the fascinating ability to self-heal; however, until recently imitating this phenomenon proved to be a huge challenge as manmade materials do not possess this ability. Due to unparalleled bending or stretching and incidental scratches, artificial skin used in robots is very susceptible to fissures and ruptures.
The research provides a new solution where a sub-nano sensor applies graphene to sense a crack as soon as it begins nucleation, and astonishingly, even after the crack has started spreading a certain distance. This technology could rapidly become practical for use in the next generation of electronics.
We wanted to observe the self-healing behavior of both pristine and defected single layer graphene and its application in sub-nano sensors for crack spotting by using molecular dynamic simulation. We were able to document the self-healing of cracks in graphene without the presence of any external stimulus and at room temperature.
Dr. Swati Ghosh Acharyya, Main Author
The results exposed that self-healing took place by natural recombination of the dangling bonds whenever inside the limit of critical crack opening displacement.
The team subjected a single layer of graphene comprising of several different defects like differently oriented pre-existing cracks and pre-existing vacancies to uniaxial tensile loading till fracture. Remarkably, once the load was tranquil, the graphene began to heal and the self-healing continued regardless of the nature of pre-existing defects in the graphene sheet.
Whatever the length of the crack, they all healed, provided the critical crack opening distance was within 0.3–0.5 nm for the sheet with pre-existing defects as well as the pristine sheet.
Simulating self-healing in artificial skin will pave the way to numerous everyday applications ranging from sensors, through to ultracapacitors and mobile devices.
The original research paper is available for free to read, download, and share on De Gruyter Online.