Dr. Abhijit Majumder's Talk

Nov 22, 2012 - 17:00

Nov 22, 2012 - 18:00

Room 118 (Creativity Hall) Ground Floor Chemical Engineering Department

Seminars

Dr. Abhijit Majumder

Abstract: Thermodynamically work of adhesion is determined by the energy released when two surfaces are brought in contact which in turn is determined by the interfacial interactions. However in our daily life we perceive adhesion as the energy or force required to separate two adhering objects. This energy of de-bonding is a strong function of the bulk mechanical properties of the separating objects. For example rheological properties play a very crucial role in determining the adhesion strength of pressure sensitive adhesives (PSAs) used in scotch tape. Other than material properties micro-patterns at the surface heavily influences adhesion by frustrating stress concentration and arresting a propagating crack. Other than surface structures sub-surface structures can also significantly influence adhesion as we demonstrated in my doctoral work. In the first part of my talk I'll elaborate how adhesion can be controlled by altering the mechanics using embedded structures. By intelligent manipulation with channel geometry and arrangement adhesion can be improved by 70 times compared to an unstructured smooth adhesive. The adhesive is reusable effective under water and shows directional adhesion depending on the arrangement of the sub-surface structures. In the second part of my talk I'll discuss how mechanics control cell behavior and fate. In cell biology form and function are inseparable and interdependent. In addition to bio-chemical signals cell behavior is strongly influenced by physical cues such as substrate topology stiffness fluid shear mechanical strain and ligand distribution which define the tissue-specific micro-environment or niche. Cells respond to these physico-chemical cues by modifying their focal adhesion and cytoskeletal/nuclear stiffness which in turn influence cell migration aggregation morphogenesis and gene expression. Therefore understanding cell mechanics is crucial to control and optimize any tissue-specific cell behavior. In addition to giving a general overview I'll specifically talk about our work aiming to understand the role of diverse mechano-signals in the context of the choice between quiescence and proliferation in mesenchymal stem cells.Biography: Abhijit did his under-graduation in Chemical Engineering from REC Durgapur and his M.Tech in Cryogenic engineering from IIT Kharagpur. Subsequently he joined IIT Kanpur for his PhD in Chemical Engineering where he worked on soft mechanics and bio-inspired adhesion. His doctoral works were published in several high-impact journals and received international awards and media attention. After finishing his PhD Abhijit joined inStem-NCBS Bangalore for his Post-doctoral work on cell-mechanics and cell biology. Presently he is continuing his Post-Doctoral research in Harvard-MIT health science and technology program (Harvard-MIT HST) where he is developing microfluidic devices for cellular and bio-medical research.