Photo: Siddharth Kankaria / Research Matters
Dropped your mobile phone? You may soon stop worrying about it, thanks to the newly discovered phenomena related to carbon nanotube foam used as a shock-absorbent material in mobile phones. As a material scientist, Prof. Praveen Kumar’s work on studying the mechanical behaviour of materials has earned him various awards, the most recent ones being the Indian National Science Academy Young Scientist Award, 2016, National Academy of Science, India -Young Scientist Platinum Jubilee awards - 2016 and Associate of Indian Academy of Science. In his Thermo-Electro-Mechanical Behaviour Lab at the Department of Materials Engineering, Indian Institute of Science, Prof. Kumar and his students study the effects of size and electric fields on mechanical properties of materials and materials processing.
The effects of electric field on mechanical properties of materials are of paramount importance at really small scales, when they are used in chips and micro-electronic apparatus found in devices like mobile phones and laptops. As devices become thinner with less airspace, they need to be shockproof, too. Prof. Kumar’s lab has experimented with carbon nanotubes to devise such a shockproof material. “The carbon nanotube cellular network that we have developed looks like a black foam which is approximately a millimetre thick. If you zoom into it, you can see it is made up of bundles of carbon nanotubes (CNTs) and there are a lot of open spaces between the CNTs, and each CNT is a multi-walled structure”, explains Prof. Kumar.
During their research, Prof. Kumar’s team found that when an electric field was applied on the new foam material, it developed a strain, which led to the foam lengthening in size. Further studies examined how fast could this material responded to stimulus and was able to absorb a shock. “These CNT foams can be used as a replacement for shock absorbent layers in devices like cell phones. They can also be used in any application that requires energy absorption. In short, these CNT foams have very good shock absorption properties, which can be improved substantially by applying an electric field across them”, says Prof. Kumar on the potential applications of these CNT foams.
Being a strong advocate of inter-disciplinary research, Prof. Kumar feels that problems of the future will need multiple perspectives to be solved, which comes from such research. Collaboration, he opines is the best way to build a team of people with different skill-sets to solve a problem. “Many a times after finishing your Ph.D., you don’t know everything! When you encounter a new problem, it will not necessarily segregate itself into a biological or a mathematical problem - Nature doesn’t know what is physics or chemistry or biology, or even what science is and what isn’t! It is we who have defined these categories”, he asserts.
Prof. Kumar attributes the success of his life and his lab to multiple players – his family, his students, and the institute. “The most important thing in IISc is that its atmosphere allows you to do whatever you want to do. And in some sense, in very subtle way, it also wants you to excel in whatever you are doing! The environment that IISc has doesn’t let you slow down”, he quips. “Who you are, is not who you are, on your own. It’s a process or a journey, where you find people – who can be anywhere – that influence you”, adds Prof. Kumar recalling those who have shaped his journey so far, as he signs off.