We would have admired at many Sci-Fi characters and the gadgets they use. However, it was hard to accept the reality that they don’t exist in real time. Surprisingly, I used to stay in the world of illusion and have always wondered why don’t we have one like that. Therefore, Harry Potter’s invisible cloak was one special thing that I fantasied with. He used the cloak to cover himself to stay invisible from others glimpse. In addition, facts in Indian mythologies also conveys that our ancestors had made warships that were invisible to their enemies’ sight. Hence, our imaginations fiddled around with objects that nature did not disclose us to.
At many instances literary pieces provoke people in developing revolutionary ideas. One such thing is the invisible materials. In general, all objects that we see, absorbs light and reflects a part of it and some materials refracts the light. We would have learnt this optical theory in our school days. For instance, let us consider an object which absorbs light completely and refracts them by constraining reflection process. Eventually, we had visualised a hypothetical material which is invisible to our eyes. Therefore, this hypothesis defines an invisible material and such materials are scientifically categorised into as “Meta materials” which means they cannot be found in nature.
It is evident to us that Meta materials never existed naturally in the world for us to explore and commercialise it. Even though people haven’t harnessed much of them yet, they had proved to the world that nothing can be fictitious over a longer stay. Firstly, people had started researching on Meta materials especially, discovering different methods to synthesis them. Apparently, it is found to be similar to the formation of DNAs. People are now working at Nano-levels for the synthesis of Meta materials, as it includes making tools that can be used to operate at Nano levels. Hence, people have to work at Nano-levels to build up a material to macroscopic size.
Optical cloaking using Meta materials was made possible by Wenshan Cai, Uday K. Chettiar, Alexander V. Kildishev and Vladimir M. Shalaev. They had manipulated electromagnetic waves producing new functionalities such as cloak of invisibility based on coordinate transformation principle. However, there were many cloaking techniques that renders macroscopic invisibility but then they had moved on with this technique. They had proposed a cylindrical cloak which is non-magnetic in nature and operated at optical frequencies. Thus, this rudimentary design had helped them reach a step that is closer to ultimate optical invisibility.
A team of researchers consisting of Jong Bum Lee, Songming Peng, Dayong Yang, Young Hoon Roh, Hisakage Funabashi, Nokyoung Park, Edward J. Rice, Liwei Chen5, Rong Long, Mingming Wu and Dan Luo had made Mechanical Meta material from DNA hydrogel. This material showed different mechanical properties, which exhibited solid like characters in water and liquid like characters when taken out of water. Isn’t it bizarre to know this. Interestingly, those were prepared using DNA as the building block. They had used polymerase enzyme to elongate DNA chains and weave them non-covalently into a hydrogel. The hydrogel had inherent shape which it regained even after undergoing deformations. They can be used in electric circuit that uses water as switch.
There are different Meta materials that are now prevailing in the world. Some of them have unusual electromagnetic or acoustic properties that allow them to be used as super lenses, super sound absorbers and many such kinds. Therefore, I would like to make a point clear that this is a very good example of converting a barrier which was considered impossible by many had been proved to be possible through human intelligence. Only thing I would like to emphasis on is that we have to generate more creative ideas which may or may not be attainable by us at present but it shall be tangible at future.