Siddhartha Das
Postdoctoral Researcher
Physics of Fluids Group, Department of Applied Physics
University of Twente, Enschede, the Netherlands
AREA OF INTEREST:
Investigations of fluid flow and analysis of separation, reaction and dynamics of biological
macromolecules in micro and nanochannels. Study of nanobubble formation in different
geometries in the open and in confinements, under different electrohydrodynamic conditions.
CORRESPONDENCE DETAILS:
Permanent address: Flat 3E, Sankosima Apartment
56, Mahesh Paul Lane,
Santragachi
Howrah – 711 104
Present Address: Room 249, Building MEANDER
Chair, Physics of Fluids
Faculty of Scinece and Technology,
University of Twente
Drienerlolaan 5, 7522 NB, Enschede, The Netherlands
Telephone Number : +91-9239538214 (India), +31 (0) 53 489 2487 (The Netherlands)
E-mail: siddhartha_iit@yahoo.com / siddhartha.iit@gmail.com
PERSONAL DETAILS:
Date of Birth: 7th May, 1982
Nationality: Indian
Parents: Pradip Ranjan Das and Manju Das
Spouse: Urmita Sengupta
Mother Tongue: Bengali
Other Languages Known: English, Hindi
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EDUCATION:
Degree
Board/Council/Univ.
Postdoctoral
Researcher
(Supervisor: Prof. Detlef
Lohse)
PhD
(Supervisor: Prof.
Suman Chakraborty)
B.Tech. (Hons)
(Mechanical)
Physics of Fluids Group,
Dept. of Applied Physics
University of Twente,
Enschede, the Netherlands
Indian Institute of
Technology, Kharagpur,
India
Indian Institute of
Technology, Kharagpur,
India
West Bengal Council of
Higher Secondary
Education, India
West Bengal Board of
Secondary Education, India
12th Standard
10th Standard
Percentage
/CGPA
Year Of
Passing
October, 2009
to
October, 2011
Thesis
Submitted on
May, 2009
8.9/10
2005
89.4 %
2001
89 %
1999
HONOURS AND ACHIEVEMENTS:
?
Selected for Non-EU Postdoctoral Fellowship (for Indian Students) by Belgium
Federal Science Office for 2009-2010 (Offer Declined).
?
Recipient of prestigious High Value Fellowship for PhD, offered by Indian Institute
of Technology, Kharagpur for the period 2007-2009.
?
Recipient of National Doctoral Fellowship, offered by All India Council of Technical
Education.
?
Only STUDENT participant to give Oral Presentation in Singapore International
Chemistry Conference 5 & APCE Asia Pacific International Symposium on
Microscale Separation and Analysis, 2007 (16-19, December, 2007 Singapore).
?
Selected by Indo-US Joint Centre for Advanced and Futuristic Manufacturing to serve
as a Junior Specialist for a period of one month (August 2006) at University of
California, Irvine.
?
Selected by Department of Mechanical Engineering, Indian Institute of
Technology, Kharagpur to do direct PhD (without Masters) after B-Tech on the
basis of excellent Academic and Project performances in the Undergraduate Level.
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?
Recipient of the Innovative Student Projects Award-2005 (B-Tech level) offered by
Indian National Academy of Engineering for the thesis titled “Modeling of Coupled
Momentum, Heat and Solute Transport during DNA Hybridization in a Microchannel
in Presence of Electroosmotic Effects and axial Pressure Gradients.”
?
Recipient of the S.P. Sengupta Memorial Award-2005, offered by Indian Institute
of Technology, Kharagpur for the best project on Computational Fluid Dynamics
for the thesis titled “Modeling of Coupled Momentum, Heat and Solute Transport
during DNA Hybridization in a Microchannel in Presence of Electroosmotic Effects
and axial Pressure Gradients.”
?
Ranked 4th in a batch of around 100 students at the B-Tech level.
?
Secured a rank of 15 in West Bengal Joint Entrance Examination (WBJEE)
(Engineering) among around 40,000 candidates.
?
Secured a rank of 740 in Indian Institute of Technology Joint Entrance
Examination (IITJEE) among around 1,50,000 candidates.
PUBLICATIONS:
Book Chapter
Chapter titled “Polymer Transport in Nanochannels” by Suman Chakraborty and Siddhartha
Das to appear in the Book entitled “Microfluidics and Nanofluidics Handbook: Fabrication,
Implementation and Applications-Vol II” published by Taylor and Francis Group
International Journal Papers (in Reverse Chronological Order):
1. Siddhartha Das and Suman Chakraborty, “Influence of Streaming Potential on the
Transport and Separation of Charged Spherical Solutes in Nanochannels Subjected to
Particle-Wall Interactions” Langmuir, Vol-25, 9863-9872 (2009).
2. Suman Chakraborty and Siddhartha Das, “Transport of Flexible Molecules in
Narrow Confinements” (Invited Review: to appear in the First Issue of the journal
International Journal of Micro and Nanoscale Transport Processes)
3. Siddhartha Das and Suman Chakraborty, “Augmented surface adsorption
characteristics by employing patterned microfluidic substrates in conjunction with
transverse electric fields”, Microfluidics and Nanofluidics (DOI 10.1007/s10404009-0462-1).
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4. Tamal Das, Siddhartha Das and Suman Chakraborty, “Influences of Streaming
Potential on Cross Stream Migration of Flexible Polymer Molecules in Nanochannel
Flows” The Journal of Chemical Physics, Vol-130, 244904 (2009).
(This paper has been selected for the July 1, 2009 issue of Virtual Journal of Biological Physics
Research in the section “Fundamental Polymer Statics/Dynamics”. The Virtual Journal, which is
published by the American Physical Society and the American Institute of Physics in cooperation
with numerous other societies and publishers like is an edited compilation of links to articles from
participating publishers, covering a focused area of frontier research)
5. Siddhartha Das and Suman Chakraborty, “Transport and Separation of Charged
Macromolecules under Nonlinear Electromigration in Nanochannels” Langmuir,
Vol-24(15), 7704-7710 (2008).
6. Suman Chakraborty and Siddhartha Das, “Streaming Field Induced Convective
Transport and its Influence on the Electroviscous effects in Narrow Fluidic
Confinements Beyond the Debye Huckel Limits” Physical Review E, Vol-77, 037303
(1-4) (2008).
7. Ruth Lambert, Siddhartha Das, Marc Madou, Suman Chakraborty and Roger
Rangel, “Simulation of a Moving Mechanical Actuator for Fast Biomolecular
Synthesis Process” International Journal of Heat and Mass Transfer, Vol-51,
4367-4378 (2008).
8. Siddhartha Das and Suman Chakraborty, “Separation of Charged Macromolecules
in Nanochannels within the Continuum Regime: Effects of Wall Interactions and
Hydrodynamic Confinements” Electrophoresis, Vol – 29, 1115-1124 (2008).
(Published in Special Issue: Fundamentals of Electrophoresis).
9. Siddhartha Das, Kapil Subramanian and Suman Chakraborty, “Analytical
Investigations on the Effects of Substrate Kinetics on Macromolecular Transport and
Hybridization through Microfluidic Channels” Colloids & Surfaces B:
Biointerfaces, Vol – 58, 203-217 (2007).
10. Siddhartha Das and Suman Chakraborty, “Transverse electrodes for improved DNA
hybridization in microchannels” AIChE Journal, Vol – 5, 1086-1099 (2007).
11. Siddhartha Das and Suman Chakraborty, “Augmentation of macromolecular
adsorption rate through Transverse Electric Fields generated across Patterned Walls
of a Microfluidic Channel” Journal of Applied Physics, Vol – 99, pp- 1-8 (2006).
(This paper has been selected for the July 15, 2006 issue of Virtual Journal of Biological Physics
Research in the section “Instrumentation Development”).
12. Siddhartha Das and Suman Chakraborty, “Analytical Solutions for Velocity,
Temperature and Concentration Distribution in Electroosmotic Microchannel Flows
of a Non-Newtonian Bio-fluid” Analytica Chimica Acta, Vol – 559, pp- 15-24
(2006).
13. Siddhartha Das, Tamal Das and Suman Chakraborty, “Analytical Solutions for the
rate of DNA hybridization in a microchannel in the presence of pressure-driven and
electroosmotic flows” Sensors and Actuators B, Vol -114, pp- 957-963 (2006).
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14. Siddhartha Das, Tamal Das and Suman Chakraborty, “Modeling of coupled
momentum, heat and solute Transport during DNA hybridization in a microchannel in
presence of electro-osmotic effects and axial pressure gradients” Microfluidics and
Nanofluidics, Vol - 2, pp- 37-49 (2006).
International Conference Proceedings (in Reverse Chronological Order):
1. Siddhartha Das and Suman Chakraborty, “Influence of Electric Double Layer
conductivity on the electroviscous effects in narrow fluidic confinements”, 20th
National & 9th ISHMT-ASME Heat and Mass Transfer Conference, January 4-6,
2010, IIT Bombay, India.
2. Siddhartha Das and Suman Chakraborty, “Electroviscous Effects in Narrow Fluidic
Confinements beyond the Debye-Hückel Limits” IISc Centenary-International
Conference on Advances in Mechanical Engineering (IC-ICAME), July 2-4,
2008, Bangalore, India.
3. Sisir Das, Siddhartha Das and Suman Chakraborty, “Molecular Dynamics
Simulation of Water Flow through Nanochannels”, 19th National & 8 th ISHMTASME Heat and Mass Transfer Conference, January 3 - 5, 2008, JNTU
Hyderabad, India.
4. Siddhartha Das, Sourav Singh and Suman Chakraborty, “Time-Periodic
Electroosmotic Transport of a non-Newtonian Bio-fluid”, 19th National & 8th
ISHMT-ASME Heat and Mass Transfer Conference, January 3 - 5, 2008, JNTU
Hyderabad, India.
5. Siddhartha Das and Suman Chakraborty, “Role of Substrate Kinetics on
Macromolecular Transport and Hybridization in Microchannels”, 19th National &
8th ISHMT-ASME Heat and Mass Transfer Conference, January 3 - 5, 2008,
JNTU Hyderabad, India.
6. Siddhartha Das, Saugata DuttaRoy and Suman Chakraborty, “Nonlinear Effects in
Electrokinetic Separation of Charged Macromolecules in Nanochannels”,
Proceedings of SICC5/APCE 2007, December 16-19, 2007, Suntec City,
Singapore.
7. Siddhartha Das, Tamal Das and Suman Chakraborty, “An Integrated Thermo-Fluid
Analysis of Electroosmotic Separation of Biological Macromolecules in
Microchannels”, 18th National & 7 th ISHMT-ASME Heat and Mass Transfer
Conference, January 4 - 6, 2006, IIT Guwahati, India.
Invited Talks
1. Talk on “Electroviscous Effects in Narrow Fluidic Confinements” in IISc Centenary
International Conference on Advances in Mechanical Engineering (IC-ICAME),
held at Bangalore, India (July, 2008).
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2. Talk on “Nonlinear Effects in Electrokinetic Separation of Charged Macromolecule
in Nanochannels” in Singapore International Chemistry Conference-5 (SICC5)
held at Suntec City, Singapore. (December, 2007).
3. Talk on “Combined pressure-driven and electroosmotic microchannel transport for
enhanced DNA Hybridization” in Department of Mechanical Engineering,
University of California, Irvine, USA (August, 2006).
Abstract of the PhD Thesis
Title: Electrokinetic Transport and Separation in Nanofluidic Channels
Nanofluidics primarily encompasses the fundamental principles and applications
concerning fluid flow and transport processes in conduits having at least one characteristic
dimension less than 100 nm. Over such length scales, extremely large surface area-to-volume
ratios of the devices may give rise to intriguing transport phenomena, remarkably distinctive
as compared to what is observed in macrofluidic or microfluidic systems.
The present study focuses on three important and inter-related facets of transport
phenomena in nanofluidic channels. First, a comprehensive mathematical model is developed
to describe electroviscous effects in nanochannels, which may originate from the fact that the
counterions in the mobile part of the electrical double layer (EDL) are preferentially
transported towards the down-stream end of the flow conduit with a pressure-driven liquid
motion. This causes an electrical current, known as the streaming current, to flow in the
direction of the imposed fluid motion. However, the resultant accumulation of ions in the
downstream section of the channel sets up its own induced electrical field, known as the
streaming potential. This field, in turn, generates a current to flow back against the direction
of the pressure-driven flow, so as to enhance the effective viscosity of flow (an artifact also
known as electroviscous effect).
A novel mathematical model is first developed in this work to predict the streaming
potential and the resulting electroviscous effects in nanochannels, with adequate
considerations of ionic advection due to streaming field induced back electroosmosis, in
addition to the pressure-driven ionic transport. In deriving the pertinent equations, it is
assumed that the transport phenomena may be described by the continuum conservation
equations with appropriate modifications to accommodate special features of interfacial
phenomena at small scales. This approach may be adequate for liquid flow systems with
characteristic length scales not falling below the order of 1 nm.
The fundamental electrokinetic model developed in this work is further utilized to
assess the implications of confinement-induced hindered diffusive transport and wall-particle
interaction forces (like EDL and van der Waals interactions) on the separation of finite sized
charged species in nanochannels. A perturbation-analysis based species transport model is
developed to address the unique features of these interaction mechanisms. This model is
further enhanced to assess the implications of streaming potential on the transport and
separation of finite-sized particles in nanochannels. It is revealed that wall-particle
interactions as well as streaming potential effects may play decisive roles towards dictating
the resolution of separation, in a manner that is conspicuously contrasting as compared to
microchannel based separation.
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Finally, the effects of streaming potential and confinement induced non-trivial
interactions on the dynamics of a flexible polymer molecules in nanochannels are studied in
this work. An augmented Brownian dynamics model is developed in order to cater these
specific needs. Significant detailed insights are obtained on the implications of nano-scale
transport on the center of mass distributions of these polyelectrolyte chains.
References
1. Dr. Suman Chakraborty (PhD Thesis Advisor), Professor, Department of Mechanical
Engineering, Indian Institute of Technology, Kharagpur.
Email: suman@mech.iitkgp.ernet.in
Phone : +91-9831402939 (Mobile), +91-3222282990 (Office).
2. Dr. S. K. Som, Professor, Department of Mechanical Engineering, Indian Institute of
Technology, Kharagpur.
Email: sksom@mech.iitkgp.ernet.in
Phone : +91-3222282979 (Residence), +91-3222282978 (Office).
3. Prof. Dr. Detlef Lohse (Postdoctoral Advisor), Chair, Physics of Fluids, Faculty of
Science and Technology, University of Twente, Enschede, the Netherlands
Email: lohse@tnw.utwente.nl
Phone: [31]-53-489-8076, Fax: [31]-53-489-806.
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