Research Interests:

Fluid Dynamics with Ions and Proteins

Fluid dynamics on the micro and nano scale has emerged as a fascinating topic of multidisciplinary research that continues to provide new insights. In particular, fluid dynamics of an aqueous fluid containing ions and proteins is even more fascinating as it occurs in the presence of a number of different phenomena and different physics. Consider, for instance, a high-mass charged protein suspended in an ionic solution containing low-mass positive and negative (salt) ions near the surface of a nanowire channel. The problem is to determine the surface charge profile near the nanowire surface (within 1-3 nm) by detecting conductance or differential conductance change in the nanowire due to the proximity of the protein molecule. This seemingly innocuous problem contains fluid (hydro) dynamics, electrostatics (governed by the Poisson equation, Debye screening and dipolar separation), and electrodynamics (representing the binding and unbinding events, and manipulation of the protein or ions with frequency dependent electric fields). In addition, statistical mechanics plays an important role in governing many aspects of this process. The binding rate is temperature (kT) dependent, which is described by standard statistical mechanics. The protein molecule’s movement is diffusion-limited. Even the microfluidic noise due to moving ions (surrounding the nanowire surface) should be defined by transport equations. However, formal theory for this multi-physics problem is yet to be done. Even simulations are challenging as there are multiple scales in the problem, and finite-element approaches do not work for simultaneous solutions of multiple types of physics with varying scales and boundary conditions. The primary goal of my group is to better define the phenomenology by a series of comprehensive measurements with unprecedented sophistication.

Selected Publications:

“Autoassociative Memory and Pattern Recognition in Micromechanical Oscillator Network”, Ankit Kumar and Priitiraj Mohanty, Scientific Reports 7, 411 (2017)

“Optical wireless information transfer with nonlinear micromechanical resonators”,
Joseph A. Boales, Farrukh Mateen and Pritiraj Mohanty, Microsystems & Nanoengineering 3, 17026 (2017)

“Wireless actuation of micromechanical resonators” Farrukh Matteen, Carsten Maedler, Shyamsunder Erramilli and Pritiraj Mohanty, Microsystems and Nanoengineering 2, 16036 (2016)

“Dissipation in Nanoelectromechanical Systems (Review)”, Matthias Imboden and Pritiraj Mohanty, Physics Reports 534, 89 (2014)

“Sensing of the melanoma biomarker TROY using silicon nanowire field-effect transistors”, Carsten Maedler, Daniel Kim, Remco A. Spanjaard, Mi Hong, Shyamsunder Erramilli, Pritiraj Mohanty, ACS Sensors 1, 696 (2016)

For a full list of publications, please see the attached CV.