A rigid body can have 6 degrees of freedom, namely 3 translational and 3 rotational degrees of freedom. These translational degrees of freedom have been well explored in optical tweezers. Further, in the nomenclature of the airlines, the yaw degree of rotational freedom has also been conventionally well explored in tweezers. But the pitch and roll degrees are only beginning to be explored. We at the optical tweezers lab explore this mode of rotation and study their application into soft and biological systems. For example, we study the cell membrane fluctuations while introducing local "slope" fluctuations and then explore intracellular viscoelasticity using conventional thermal translational and rotational motion. We also show the many ways in which pitch motion can be generated in optical tweezers to even execute pitch torque wrench. We also touch upon a few other systems that we explore using optical tweezers in our lab like using upconverting particles to enhance Fluorescence Correlation Spectroscopy, study waves on the interface of sessile water droplets, micropatterning using thermo-optical tweezers etc.
Basudev Roy did his integrated MSc from Indian Institute of Technology Kharagpur. He did his PhD from Indian Institute of Science Education and Research Kolkata in the year 2015. Thereafter he did his postdoc at the University of Tuebingen, Germany where he was also an Alexander von Humboldt fellow. He joined IITM in April 2017. He got the DBT-Wellcome Trust Intermediate Fellowship in the year 2020 and the Institute Research and Development Award in the year 2021.