Undergraduate Project, Mentored by Dr. Krishnacharya Khare, Dept. of Physics, IIT Kanpur

• Demonstrated different approaches for fabricating surfaces possessing reentrant curvature
• Used Cassie-Baxter and Wenzel model to plot apparent contact angle with respect to different configurations possible by changing geometric parameters, while mimicking the terminal shape of gecko’s setae
• Showed how roughness alone, if made of a specific doubly reentrant structure that enables very low liquid-solid contact fraction, can render the surface of any material super-repellent
• Modelled contact angle dependence on different physical parameters by 3-D plots on PYTHON code
• Studied various other methods for making surfaces hydro & oleophobic like electro-wetting

Can be used for different Nano-devices which do not want to interact with different bio-liquids they encounter

Pillars are characterized by a height of ’h’ a tip radius of ’c’ and a stem radius of ’a’. Center to center distance between the pillars is given by ’b’. where theta and theta_star are equilibrium contact angle and the apparent contact angle on the textured surface, respectively; ’r’ is a roughness factor defined as the ratio of the actual area over the apparent area and phi is defined as the fraction of solid-liquid interface.