Japanese scientists have developed a new material whose properties are dominated by electrostatic repulsion – the same force that makes our hair stand on end when we touch a van generator – rather than attractive interaction.
Up to now, man-made materials have not taken advantage of this phenomenon, but nature has. Cartilage owes its ability to allow virtually frictionless mechanical motion within joints, even under high compression, to the electrostatic forces inside it.
“Materials of this kind could be used in the future in various areas from regenerative medicine to precise machine engineering, by allowing the creation of artificial cartilage, anti-vibration materials and other materials that require resistance to deformation in one plane,” said Yasuhiro Ishida from the RIKEN Center for Emergent Matter Science in Japan.
The team found that when titanate nano-sheets are suspended in an aqueous colloidal dispersion, they align themselves face-to-face in a plane when subjected to a strong magnetic field.
The field maximises the electrostatic repulsion between them and entices them into a quasi-crystalline structure, naturally orienting themselves face to face, separated by the electrostatic forces between them.
Along with colleagues from the National Institute of Material Science and the University of Tokyo, the team created the new material.
The findings appeared in the journal Nature.
Mingjie Liu, Yasuhiro Ishida, Yasuo Ebina, Takayoshi Sasaki, Takaaki Hikima, Masaki Takata, and Takuzo Aida, “An anisotropic hydrogel with electrostatic repulsion between cofacially aligned nanosheets“, Nature, doi: 10.1038/nature14060