Research Overview: Diganta Dutta

Cancer describes a wide range of diseases that stem from unregulated cell growth. For our research, we chose to study leukemia through experimentation with Jurkat cells. Results from experimental work demonstrated that their mechanical properties and ultra-structure differed at the nano-metric level. Two examples of local material & chemical properties that we mapped are the modulus of elasticity and the cell membrane surface charge density. These differ between healthy and cancerous cells; mapping these quantities can be helpful in the future for the creation of biomedical devices, medications, and techniques that can exploit these properties. 

Figure: Cancer (Jurkat) cell imaging using AFM

Figure: Cancer (Jurkat) cell imaging using AFM

Working with cartilage, we hypothesized that the nanostraws within cartilage were responsible for fluid transport within. We used AFM to investigate and image nanostraws of collagen found within costal cartilage, gaining valuable data concerning the Young’s modulus of elasticity of the collagen nanostraws and how the straws differ under different regimes of treatment. Potentially, the work can give further clues into how the nanostraws' properties factor into the occurrence of these deformities.

Figure: Human Costal cartilage nanostraw characterization

Figure: Human Costal cartilage nanostraw characterization

The third project involves the creation and testing of a shear stress sensor for the measurement of multi-phase-fluid-structure – microfluidic interactions, which takes advantage of a microfluidic cavity that is filled with an electrolytic fluid. The membrane itself forms instability wave modes that induce fluid motion within the cavity as a result of stretching and flexing the membrane, which is super hydrophobic. Two electrodes within make velocimetry measurement of the induced convection created.

The membrane deforms at the nanoscale due to external airflow, creating an internal convection in the cavity wherein two electrodes create an electric field across the created internal convection which produces a measurable current through a non-faradic interaction; all of this is caused by shear forces external to the membrane and therefore provides a direct relationship between the current produced and external shear forces.

Figure: Microfluidics based shear stress sensors

Figure: Microfluidics based shear stress sensors