Design and Fabrication of Active Bio-hybrid Microsystems for Applications in Biology and Medicine.
My primary research focus is to develop functional micro/nanofabricated systems for fundamental biology and translational medicine applications. My previous research at CWRU included engineering blood vessel mimicking microchannels to investigate blood cell and endothelial wall interactions and developing point-of-care platforms for diagnosis and monitoring of blood disorders. In MPI-IS, I am interested in bio-hybrid mobile microrobotic systems with intelligent control schemes for in-vitro and in-vivo micro-manipulation, biosensing, and drug delivery applications.
PhD: Mechanical and Aerospace Engineering, Case Western Reserve University, OH, USA, 2016
Surface tension gradients induce Marangoni flow, which may be exploited for fluid transport. At the micrometer scale, these surface-driven flows can be more significant than those driven by pressure. By introducing fluid-fluid interfaces on the walls of microfluidic channels, we use surface tension gradients to drive bulk fluid flows. The gradients are specifically induced through thermal energy, exploiting the temperature dependence of a fluid-fluid interface to generate thermocapillary flow. In this report, we provide the design concept for a biocompatible, thermocapillary microchannel capable of being powered by solar irradiation. Using temperature gradients on the order of degrees Celsius per centimeter, we achieve fluid velocities on the order of millimeters per second. Following experimental observations, fluid dynamic models, and numerical simulation, we find that the fluid velocity is linearly proportional to the provided temperature gradient, enabling full control of the fluid flow within the microchannels.
Kim, M., Alapan, Y., Adhikari, A., Little, J. A., Gurkan, U. A.
Microcirculation, 24(5):e12374, July 2017 (article)
Abstract Objectives The advancement of microfluidic technology has facilitated the simulation of physiological conditions of the microcirculation, such as oxygen tension, fluid flow, and shear stress in these devices. Here, we present a micro‐gas exchanger integrated with microfluidics to study RBC adhesion under hypoxic flow conditions mimicking postcapillary venules. Methods We simulated a range of physiological conditions and explored RBC adhesion to endothelial or subendothelial components (FN or LN). Blood samples were injected into microchannels at normoxic or hypoxic physiological flow conditions. Quantitative evaluation of RBC adhesion was performed on 35 subjects with homozygous SCD. Results Significant heterogeneity in RBC adherence response to hypoxia was seen among SCD patients. RBCs from a HEA population showed a significantly greater increase in adhesion compared to RBCs from a HNA population, for both FN and LN. Conclusions The approach presented here enabled the control of oxygen tension in blood during microscale flow and the quantification of RBC adhesion in a cost‐efficient and patient‐specific manner. We identified a unique patient population in which RBCs showed enhanced adhesion in hypoxia in vitro. Clinical correlates suggest a more severe clinical phenotype in this subgroup.
Our goal is to understand the principles of Perception, Action and Learning in autonomous systems that successfully interact with complex environments and to use this understanding to design future systems