​Date: Thursday, Apr 27

Time: 15:00-16:00

Location: Center, level B, B503

Speaker: Prof. Pavan Kumar Gopalapura Venkataramu, IISER PUNE.

Title :  Soft Matter in Opto-Thermal Gradients : Evolutionary Dynamics and Pattern Formation 

Abstract:
Microscopic colloids are basic building blocks of soft and biological matter. They also serve as experimental test-beds of Brownian dynamics. By illuminating light-absorbing colloids with a laser beam, one can observe the so-called 'hot-Brownian motion'. This out-of-equilibrium colloidal system can form unconventional assemblies and exhibit evolutionary dynamics that can be tuned by light. In this talk, I will show how structuring optical [1], plasmonic [2] and optothermal forces [3] can influence the translational and rotational dynamics of Brownian colloids. I will further discuss the emergence of unconventional patterns of colloidal assembly that can mimic dynamic networks. I will conclude with a discussion on some challenges and opportunities of studying structured light-biological matter interactions.

[1] Optothermal Evolution of Active Colloidal Matter in a Defocused Laser Trap. ACS Photonics 2022, 9 (10), 3440–3449.

[2] Optothermal Pulling, Trapping, and Assembly of Colloids Using Nanowire Plasmons. Soft Matter 2021, 17 (48), 10903–10909.

[3] Plasmofluidic Single-Molecule Surface-Enhanced Raman Scattering from Dynamic Assembly of Plasmonic Nanoparticles.
Nat Commun 2014, 5 (1), 4357.