Title : Exploring the Pattern Formation of Bio-colloids Through Drying Droplets.
Speaker : Dr. Anusuya Pal, University of Warwick, UK.
Date : 20/10/2022, 05:30 PM , Ramanujan Hall, IISER Tirupati Transit Campus.
The drying of a sessile droplet containing non-volatile solutes induces a plethora of beautiful depositing patterns. In fact, when these droplets are dried under uniform conditions (diameter, surface, humidity, etc.), the morphological pattern appears to be a unique fingerprint of these non-volatile solutes present in the droplet. Understanding the mechanism of the emerging morphological pattern formation is vital from a fundamental point of view and has significant ramifications for applications, ranging from coating to disease detection. It has been found that the patterns of the bio-fluids (blood, plasma, etc.) have the potential to distinguish between healthy and diseased bio-fluids and identify the stages of different diseases (cancer, thalassemia, etc.). These bio-fluids’ different physical and chemical properties have been qualitatively linked to disease; however, the quantitative relationship between such patterns and disease recognition remains poorly understood. In this talk, I will discuss the simple and ubiquitous drying process that involves numerous physics from droplet wetting, flow fields, and mass transportation to evolving morphological patterns. I will first showcase the drying patterns of a simple bio-colloidal system (protein with de-ionized water), then, in the presence of liquid crystals (LCs), and end with the naturally occurring complex system, such as healthy human blood. Different microscopy and image processing techniques are used for quantifying these patterns. The complementary technique, such as contact angle measurement, provides insights into the wetting dynamics during the drying process. Our experimental findings show that the patterns of different proteins are pre-dominantly dependent on protein-protein interactions. The LCs’ texture is influenced by different protein droplets indicating that these bulk unaligned LCs are not always randomly distributed. Our work on human blood also uncovers an interesting sharp transition that emerged as a function of the initial concentration. Finally, I will link how these emerging patterns could be linked to different stages of any abnormalities and diseases, providing an exceptional opportunity for the droplet drying method to be used as a fast, accurate screening tool in clinical settings.
Dr. Anusuya Pal earned her Ph.D. from the Department of Physics, Worcester Polytechnic Institute (WPI), USA under the guidance of Prof. Germano Iannacchione. Prior to that, she received her Integrated Masters Degree in Physics from the University of Hyderabad, India, in 2016. She did a second M.S in Physics from the Department of Physics, WPI, in 2018. Her research interests span areas within soft condensed matter and biophysics, where the main thrust is to understand the emergent morphological patterns, interfacial properties, self-assembling mechanisms, and collective behavior. This includes colloids and suspensions, drying droplets, microbial transport, liquid crystals, complex fluids, phototaxis, etc. She has been actively involved in exploring the emerging patterns of different bio-fluids. Currently, she is pursuing her Post-Doctoral research in the Department of Physics, University of Warwick, UK, under the guidance of Prof. Marco Polin. Dr. Pal has received several awards, such as the GSOFT Travel Award from the APS community and seed funding to continue her research work during her Ph.D. tenure at WPI.