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Biography of Basudev Roy

Educational Qualification:

1. PhD in Physics from IISER Kolkata.

2. MS in Physics from the University of Maryland, College Park, USA.

3. Integrated MSc in Physics from IIT Kharagpur. 

Professional Experience:

1. Apr 2017 - Till date: Assistant Professor at Indian Institute of Technology Madras, Chennai, India.  

2. Dec 2015 - Mar 2017:Alexander Von Humboldt Postdoctoral fellow at the University of Tuebingen, Germany.

3. Oct 2014 - Nov 2015: Postdoctoral fellow at University of Tuebingen, Germany.

Awards and Achievements:

  1. Awarded the "IISER Kolkata Alumni Award 2022" for Academic Excellence by the Indian Institute of Science Education and Research Kolkata, India.

  2. Awarded the Early Career, Institute Research and Development Award for the year 2020-21 by the Indian institute of Technology Madras, Chennai, India. 

  3. Awarded the Wellcome Trust (United Kingdom) -Department of Biotechnology (India), India Alliance Intermediate Fellowship in 2020. 

  4. Awarded the Humboldt Research Fellowship in July 2015 for continuing postdoctoral work at the University of Tuebingen, Germany.

  5. Secured 10th rank in the Physics paper in Graduate Aptitude Test in Engineering. The  percentile was 99.8. 

  6. Awarded the Institute Silver Medal upon being adjudged the best student in order of merit among students graduating with an M Sc degree in Physics by the Indian Institute of Technology, Kharagpur.

  7. Awarded the Gold Medal and Certificate of Merit for performance in the National Graduate Physics Examination, by the Indian Association of Physics Teachers.

Bio-Inspired Optical Tweezers lab

Department of Physics, IIT Madras

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Research Interests

We are an upcoming group in the Physics department of IIT Madras with primary emphasis on Optical Tweezers based study of statistical mechanics and biological systems. We are essentially going to divide our time for two topics, namely, High Resolution Imaging based systems and Optical Tweezers based systems.


We would like to probe biological systems at the single molecule level by performing high resolution imaging. Some examples of high resolution imaging tools are Dark Field Microscopy,  Interference Reflection Microscopy (IRM) and Total Internal Reflection Microscopy (TIRF). We would like to see if simple tools that enhance these techniques can challenge the state of the art in the field, namely the "Super-Resolution Microscopy". 



We would like to couple high resolution imaging systems described in the last section to optical tweezers to study biological systems. Optical Tweezers are a tightly focused beam of light which generates a three dimensional potential well for trapping microparticles. These can not only be used to apply and detect controlled forces but also controlled torques upon using birefringent microparticles. We would like to couple single biomolecules like kinesin motors and DNA to such birefringent particles and apply controlled torques to study intrinsic properties of these molecules. A rigid body can have three degrees of rotational freedom, which we call the yaw, the pitch and the roll. The yaw, or the in-plane degree of rotational freedom is well studied in optical tweezers literature. But the pitch and the roll have not. We have done some work in generating and detecting pitch motion with applications to the study of biological problems. 


We shall try to probe the interaction among different types of particles in different types of media and see how the exchange of energy takes place for equilibrium and non-equilibrium systems. 

Invited Talks:

1. "Study of soft and biological matter systems using optical tweezers", In-House Colloquium, Department of Physics, Indian Institute of Technology Madras, Chennai , 20th October, 2021.

2. "Study of soft matter systems using rotational optical tweezers", Indian Institute of Technology, Tirupati, 30th October 2019. 

3. "Determination of twisting of kinesin molecules during stepping", OSA Biophotonics congress: Optics in the life sciences,  AM2E.1, Tucson, Arizona, 15th April, 2019. 

4.“Optical Tweezers for determination of rotational motion in the mesoscopic domain”, Indian Institute of Science Education and Research, Kolkata, India, 19th Dec 2017. 

5. “Optical Tweezers for determination of rotational motion in the mesoscopic domain”, Institute of Nano Science and Technology, Mohali, India, 18th Sept 2017

Conference Proceedings:

1. "Generation of active motion from optically trapped upconverting nanoparticles", Sumeet Kumar, Rahul Vaippully and Basudev Roy, SPIE Optics and Photonics, San Diego, 11798-89, August 2021. 

2. "Generation of pitch rotational torque wrench using two-beam optical tweezers on a birefringent particle", Lokesh Muruga, Rahul Vaippully and Basudev Roy, SPIE Optics and Photonics, San Diego, 11798-46, August 2021. 

3. "Pitch rotation of hexagonal microparticle using single beam thermo-optical tweezers", Sumeet Kumar and Basudev Roy, SPIE/COS Photonics Asia, 1155610, October 2020. 

4. "Determination of local cell membrane slope fluctuations using the pitch rotational mode of optical tweezers", Rahul Vaippully, Vaibavi Ramanujan, Manoj Gopalakrishnan, Saumendra Bajpai and Basudev Roy, SPIE Optics and Photonics, San Diego, 11463-39, August 2020.

5. "Generation of thermo-optical instability mediated by thermophoresis in a sessile water droplet", Muruga Lokesh, Rahul Vaippully, Anvitha Reddy, Basudev Roy, SPIE Optics and Photonics, San Diego, 11463-77, August 2020. 

6. "Characterization of emission from thermo-optical tweezers during spontaneous self-assembly", Sumeet Kumar, Rahul Vaippully, Gaurav Vaidya and Basudev Roy, SPIE Optics and Photonics, San Diego, 11463-74, August 2020. 

7. “Study of absorption and emission dipoles of upconverting nanoparticles optically trapped at the absorption resonance”, Amrendra Kumar, Bhavesh Kharbanda, M. Gunaseelan, Rahul Vaippully and Basudev Roy, SPIE Photonics Europe, 11345-35, March 2020.

8. "Determination of surface binding properties using rotational optical tweezers", Rahul Vaipully, Dhanush Bhatt, Anand Dev Ranjan, and Basudev Roy, OSA Biophotonics congress: Optics in the life sciences, AW1E.2, Tucson, Arizona, April, 2019. 


  1. “Laser Induced Micro-Bubble Based Patterning of Biological Macromolecules Towards Bio-Sensing Applications”, Subhrokoli Ghosh, Anand Dev Ranjan, Pradyoti Sarkar, Rakesh Sen, Arnab Gupta, Pei Liang, Amirul Mullick, Basudev Roy, Soumyajit Roy, Ayan Banerjee, Provisional patent application no. 202031020734 filed on 18 May 2020.

  2. "Development of a Field-Effect Device using conducting polymers such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) layers made using microbubble lithography", Basudev Roy, Ayan Banerjee, Soumya Dutta, Rahul Vaippully, Mithun Ajith, Anand Dev Ranjan, Provisional patent application no. 202141026917 filed on 16 June 2021.

Journal Publications:





1. S.Yamini, M.Gunaseelan, G.A.Kumar, Gamage Chamath Dannangoda, Karen S Martirosyan, Dhiraj K Sardar ,  Basudev Roy and J.Senthilselvan, " Tailoring the upconversion emission and magnetic properties of NaGdF4:Yb,Er by Mg2+ or Fe3+ doping and optical trapping of individual magnetic nanoparticle at NIR 980 nm", Accepted in Ceramics International (2022). 


2. Merin Jose, Muruga Lokesh, Rahul Vaippully, Dillip Satapathy and Basudev Roy, "Temporal evolution of viscoelasticity of soft colloid laden air-water interface: A multiple mode microrheology study", Accepted in RSC Advances (2022). 


3. Muruga Lokesh, Rahul Vaippully, Vidya P. Bhallamudi, Anil Prabhakar, Basudev Roy, "Realisation of pitch-rotational torque wrench in two-beam optical tweezers", Journal of Physics Communications, 5, 115016 (2021).

4. Selvam Yamini, M Gunaseelan, A Gangadharan, S.A. Lopez, Martirosyan K. S., A. Girigoswami, Basudev Roy, J. Manonmani, Jayaraman Senthilselvan, "Upconversion, MRI Imaging and Optical Trapping Studies of Silver Nanoparticle Decorated Multifunctional NaGdF4:Yb,Er Nanocomposite", Nanotechnology, 33, 085202 (2022).

5. Muruga Lokesh, Rahul Vaippully, Gokul Nalupurackal, Srestha Roy, Vidya P. Bhallamudi, Anil Prabhakar and Basudev Roy, "Estimation of rolling work of adhesion at the nanoscale with soft probing using optical tweezers", RSC Advances, 11, 34636-34642 (2021).

Highlighted in Tech Talks by IIT Madras

6. Vaibavi Ramanujam, Manoj Sivasubramaniapandian, Rahul Vaippully, Privita Edwina, Basudev Roy, Saumendra Bajpai, "Calcium-channel blockers exhibit divergent regulation of cancer extravasation through the mechanical properties of cancer cells and underlying vascular endothelial cells", Cell Biochemistry and Biophysics, 80, 171-190 (2022).

7. Amrendra Kumar, Gunaseelan M., Gaurav Vaidya, Rahul Vaippully and Basudev Roy, "Estimation of motional parameters using emission from upconverting nanoparticles optically trapped at the absorption resonance", Accepted In European Physical Journal-Special Topics (2021). 

8. Rahul Vaippully, Lokesh Muruga and Basudev Roy, "Continuous rotational motion in birefringent particles using two near-orthogonally polarized optical tweezers beams at different wavelengths with low ellipticity", Journal of Optics, 23, 094001 (2021).

9. Sumeet Kumar, Gunaseelan M., Rahul Vaippully, Ayan Banerjee and Basudev Roy, "Breaking the diffraction limit in absorption spectroscopy using upconverting nanoparticles", Nanoscale, 13, 11856 (2021). 

Highlighted in "The Hindu" newspaper.

10. Subhrokoli Ghosh, Anand Dev Ranjan, Santu Das, Rakesh Sen, Basudev Roy, Soumyajit Roy and Ayan Banerjee, "Directed self-assembly driven meso-scale lithography using laser-induced and manipulated microbubbles: complex architectures and diverse applications", Nano Letters, 21, 10 (2020). 

11. Sumeet Kumar, Amrendra Kumar, Gunaseelan M., Rahul Vaippully, Dipanjan Chakraborty, Jayaraman Senthilselvan and Basudev Roy, "Trapped in out-of-equilibrium stationary state: Hot Brownian motion in optically trapped upconverting nanoparticles", Frontiers in Physics, 8, 570842 (2020). 

12. Rahul Vaippully, Vaibavi Ramanujan, Manoj Gopalakrishnan, Saumendra Bajpai, Basudev Roy, "Detection of sub-degree fluctuations of the local cellmembrane slope using optical tweezers", Soft Matter, 16, 7606  (2020).  

13. Sumeet Kumar, M. Gunaseelan, Rahul Vaippully, Amarendra Kumar, Mithun Ajith, Gaurav Vaidya, Soumya Dutta and Basudev Roy,"Pitch-rotational manipulation of single cells and particles using single-beam thermo-optical tweezers", Biomedical Optics Express, 11, 3555 (2020). 

14. Rahul Vaippully, Vaibavi Ramanujan, Saumendra Bajpai and Basudev Roy,"Measurement of viscoelastic properties of the cellular cytoplasm using optically trapped Brownian probes"",  Journal of Physics Condensed Matter, 32, 235101 (2020).

15. Muruga Lokesh, Rahul Vaippully, Basudev Roy, "Active generation of pitch degree of rotational motion in optical tweezers", Asian Journal of Physics, 29, 177 (2020). 

16. L. Anbharasi, E. A. Bhanu Rekha, Rahul Vaippully, Basudev Roy, M Gunaseelan, S. Yamini, Venkata N.K.B .Adusumalli, Debashrita Sarkar, Venkataramanan Mahalingam, J. Senthilselvan, "Tunable Emission and Optical Trapping of Upconverting LiYF4:Yb,Er Nanocrystal", Journal of Optics and Lightwave Technology, 126, 106109 (2020).

17. Rahul Vaippully, Venkata Siva Gummaluri, C Vijayan and Basudev Roy, “Validity of cylindrical approximation for spherical birefringent microparticles in rotational optical tweezers”, Journal of Physics Communications, 4, 015005 (2020).

18. Dhanush Bhatt, Rahul Vaippully, Bhavesh Kharbanda, Anand Dev Ranjan, Sulochana K., Viraj Dharod, Dillip Satapathy and Basudev Roy, "Detection of self-generated nanowaves on the interface of an evaporating sessile water droplet", Optics Express, 27, 31900 (2019).

Highlighted in

"Down to Earth".

"Vigyan Prasar",

19. Rahul Vaippully, Dhanush Bhatt, Anand Dev Ranjan and Basudev Roy, " Study of adhesivity of surfaces using rotational optical tweezers", Physica Scripta,, 94, 105008 (2019).

20. Basudev Roy*, Avin Ramaiya and Erik Schaffer, “Determination of pitch rotation in a spherical birefringent microparticle”, Journal of Optics, 20, 035603  (2018). * Corresponding author.


  1. Mayank Chugh, Maja Reissner, Michael Bugiel, Elisabeth Lipka, Arvid Herrman, Basudev Roy, Sabine Muller, Erik Schaffer, "Phragmoplast Orienting Kinesin 2 Is a Weak Motor Switching between Processive and Diffusive Modes", Biophys. J, 115, 375 (2018). 

  2. Avin Ramaiya*, Basudev Roy*, Michael Bugiel and Erik Schaffer, “Kinesin rotates unidirectionally and generates torque while walking on microtubules”, Proceedings of National Academy of Sciences, 114, 10894 (USA) (2017).Highlighted in Science Daily.

  3. Subhrokoli Ghosh, Santu Das, Shuvojit Paul, Preethi Thomas, Basudev Roy, Partha Mitra, Soumyajit Roy, Ayan Banerjee, “In-situ self-assembly and photopolymerization for hetero-phase synthesis and patterning of conducting materials using soft-oxometalates in thermo-optical tweezers”, Journal of Materials Chemistry C, 5, 6718 (2017). Highlighted in Nature India, India Today, Business Standard. 

4. Preethi Thomas, Cuiying Pei, Basudev Roy, Ayan Banerjee, Teng Ben, ShilunQiu and Soumyajit Roy,  “Site specific supramolecular heterogenous catalysis by optically patterned soft-Oxometallate-Porous Organic Framework (SOM-POF) hybrid on a chip”, J. Mater. Chem. A, 3, 1431 (2015).

5. Basudev Roy, Manish Arya, Preethi Thomas, Julius Constantin Jurgschat,  Venkat Rao, Ayan Banerjee, Chilla Malla Reddy and Soumyajit Roy, “Controlled and continuous patterning of organic and inorganic materials by induced nucleation in an optical tweezers”,  Langmuir, 29,14733 (2013).

Funding Sources

1. Wellcome Trust-Department of Biotechnology India Alliance

2. IMPRINT program SERB, DST

3. IIT Madras, Seed, Initiation and Exploratory Grants. 

PhD Students (Thesis Defended and Submitted):

1. Sumeet Kumar

2. Rahul Vaippully

PhD Students (Ongoing):

1. C. M. Lokesh

2. Amrendra Kumar

3. Sreshtha Roy

4. N. P. Gokul

5. Jayesh Goswami

6. Snigdhadev Chakraborty

BTech and MSc Students (Thesis work completed)

1. Sarangi Suresh

2. Snigdhadev Chakraborty

3. Bhaskar De

4. Dhanush Bhatt

5. Bhavesh Kharbanda

6. Ponnapati Anvitha

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044 - 2257 4843

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