Ever wondered if cracks could lead to incredible innovations? Professor Alain Karma explains how it’s possible. Mr.Karma, a professor of Physics at the Northeastern University, was struck by the patterning of cracks and how they form complex mysterious branches. This made him show interest in studying cracks and exploring its potential. Earlier, he had studied snowflakes which has intricate crystalline branches.
On talking about how cracks can be the key to developing long-lasting batteries, Dr.Karma says, “Cellphone batteries use conventional graphite electrodes. When we charge our devices, lithium ions flow from the battery’s positive electrode (the cathode) to the negative electrode (the anode). As the battery drains, lithium moves in the opposite direction, flowing away from the anode.” Therefore, a device’s battery life depends upon how much lithium can be stored in the anode and the graphite anodes in our batteries are said to be pretty subpar at lithium storage. Anodes made from silicon, which has 10 times the charging capacity of the current anodes present, will be great for storing lithium but can swell up to 300 per cent and can crack under stress.
Karma’s research focusses on designing silicon anodes of different shapes to develop a structure that can withstand swelling without cracking, thereby increasing the charge capacity of cellphone batteries everywhere. This April, he also received a grant from the National Science Foundation to continue studying the fundamentals of crack movements.
He compares the stability of cracks in two-dimensional (say paper) and three-dimensional (say a block of cheese) surfaces and says that cracks can reach more than 90 per cent of its maximum speed in 2D whereas, in 3D the main crack splinters into tiny offshoots called microbranches.
He also says that at Northeastern they are aiming to develop a high-strength engineering material by trying to crack the mystery of how microbranching instability occurs and their work is said to include medical implications as well. This will lead to stronger materials, better batteries, and a stronger understanding of the ageing of the human body.