Research Topic: Friction between a soft patterned and stiff body in presence of boundary lubricant
Advisor: Sanjeev Kumar Gupta
While holding any object, there is an active interaction between our fingertips and the object’s surface. In such cases, sliding commences between the human finger and the counter substrate, where the contact might be intermediated by materials that can act as a lubricant. Tactile perception arises out of such active exploration of surfaces via the sense of touch. Both the normal and the frictional load applied by the human fingers play an essential role in this tactile exploration. The advances made in studying tactile friction can be used in designing haptics, prosthetics, clothes, detergents, etc. Even a complex phenomenon like tactile perception can be quantified using tactile friction. The system under study can be generalized, and the study’s goal is to investigate friction between a deformable patterned soft substrate and a stiffer substrate in the presence of boundary lubrication. Factors like elasticity, surface roughness and surface energy come together to control tactile friction. COF values were calculated using the human finger for different lubricating solutions and different substrates. All the measurements were made on an in-house developed strain gauge-based force sensor. The role of human skin, owing to its low elastic modulus and affinity for specific interactions with different molecules, cannot be understated in determining tactile friction. The experimental results are evidence for the hypothesis that any change on the interface, regardless of how small it is reflected in the friction values.