Reflectin

Reflectin is a protein originating from the Hawaiian Bobtail Squid, "Euprymna scolopes", which is native to the central Pacific Ocean. Reflectins, a recently identified protein family that is enriched in aromatic and sulphur-containing amino acids, are used by certain cephalopods to manage and manipulate incident light in their environment.

It is thought that the biophysical properties of the highly reflective and self-organizing squid protein will inform researchers about the process of “bottom-up” synthesis of nanoscale structures and could lead to the development of thin-film coatings for microstructured materials, bringing scientists one step closer to the development of an invisibility cloak.

To this aim, various research groups are using so-called metamaterials, whose nanoscale properties alter the way in which their surfaces reflect visible light. Objects are visible because light bounces off them; Researchers have found that recombinantly expressed reflectin has revealed unanticipated self-assembling and behavioural properties which suggests that reflectin can be easily processed into thin films, photonic grating structures and fibres. Theoretically, this makes it possible to develop a material which could cause incident light to pass round it. This means that it could be used in a cloak that covers objects and renders them invisible. The current research was partly funded by DARPA (the research and development arm of the Pentagon). It is thought the development of an invisibility cloak might be the ultimate aim of the project.

References

* Kramer, R. M., "et al." (2007). The self-organizing properties of squid reflectin protein. "Nature Materials" 6: 533–538. DOI|10.1038/nmat1930
* Crookes, W. J., "et al." (2004). Reflectins: The unusual proteins of squid reflective proteins. "Science" 303: 235–238.
* [http://neurophilosophy.wordpress.com/2007/06/07/invisibility-cloak-materials-made-from-reflective-self-assembling-squid-proteins/ Invisibility cloak materials made from reflective self-assembling squid proteins]