Dr. Shivaprakash Narve Ramakrishna
Dr. Shivaprakash Narve Ramakrishna
Lecturer at the Department of Materials
ETH Zürich
Additional information
Research area
- Nanotribology and nanomechanics
- Atomic force microscopy
- Surface and interfaces
- Soft matter
Dr. Ramakrishna has received his Bachelor’s and Master’s degrees from Kuvempu University, Karnataka, India. He completed his PhD in 2013 in the Department of Materials, ETH Zurich. During his PhD he carried out research on adhesion and tribology on nanoscale rough surfaces. He did his PostDoc at the Laboratory for Surface Science and Technology from 2013 until June 2015, where he investigated the frictional and mechanical properties of stratified layers of polymer brush-gel structures using the colloidal-probe AFM technique. He worked as a Senior Scientist at the Laboratory for Surface Science and Technology from June 2015 till March 2020.
His current research focuses on experimental visualization of the 3D conformation of soft microgel particles at the liquid-liquid interface, achieved through in-situ atomic force microscopy. This cutting-edge approach allows for a meticulous examination of individual particle interactions and their resulting interfacial behavior at an exceptionally high resolution.
Additional information
Publications:
2024
65. Effect of particle stiffness and surface properties on the non-linear viscoelasticity of dense microgel suspensions. Vialetto, J.; Ramakrishna, S.N.; Isa,L.; Laurati. M. J. Colloid Interface Sci. 2024, 672, 814–823.
64. The Structural Dispersity of Oligoethylene Glycol-Containing Polymer Brushes Determines Their Interfacial Properties. Pavón. C.; Ongaro, A.; Filipucci. I.; Ramakrishna, S.N.; Mattarei. A.; Isa, L.; Klok. H.; Lorandi. F.; Benetti, E. M. The Structural Dispersity of Oligoethylene Glycol-Containing Polymer Brushes Determines Their Interfacial Properties. J. Am. Chem. Soc. 2024, 146, 24, 16912–16919.
63. Modulating the conformation of microgels by complexation with inorganic nanoparticles. Vialetto, J.; Ramakrishna, S.N.; Stock, S.; von Klitzing, R.; Isa,L. J. Colloid Interface Sci. 2024, 672, 797–804.
62. Measuring Rolling Friction at the Nanoscale. Scherrer, S.; Ramakrishna, S, N.; Niggel, V.; Spencer, N. D; Isa, L. Langmuir 2024, 40, 13, 6750–6760.
2023
61. Liposomal aggregates sustain the release of rapamycin and protect cartilage from friction. Bordon, G.; Ramakrishna, S, N.; Edalat, S, G.; Eugster, R.; Arcifa, A.; Vermathen, M.; Aleandri, S.; Bertoncelj, M, F.; Furrer, J.; Vermathen, P.; Isa, L.; Crockett, R.; Distler, O.; Luciani, P.; J. Colloid Interface Sci. 2023, 650, 1659-1670
60. Exploring the 3D Conformation of Hard‐Core Soft‐Shell Particles Adsorbed at a Fluid Interface. Vialetto, J.; Camerin, F.; Ramakrishna, S.N.; Zaccarelli, E.; Isa, L. Adv. Sci. 2023, 2303404, 1-9.
2022
59. In situ imaging of the three-dimensional shape of soft responsive particles at fluid interfaces by atomic force microscopy. Vialetto, J.; Ramakrishna, S.N.; Isa, L. Science Advances 2022, 8, 45. 1-10.
2021
58. Reactive-Oxygen-Species-Mediated Surface Oxidation of Single-Molecule DNA Origami by an Atomic Force Microscope Tip-Mounted C60 Photocatalyst. Ray, A.; Passiu, C.; Nasuda, M.; Ramakrishna, S. N.; Rossi, A.; Kuzuya, A.; Spencer, N. D.; and Yamakoshi, Y. ACS Nano 2021, 15, 12, 19256–19265
57. Dispersity within Brushes Plays a Major Role in Determining Their Interfacial Properties: The Case of Oligoxazoline-Based Graft Polymers. Romio, M.; Grob, B.; Trachsel, L.; Mattarei, A.; Morgese, G.; Ramakrishna, S. N.; Niccolai, F.; Guazzelli, E.; Paradisi, C.; Martinelli, E.; Spencer, N. D.; Benetti, E. M. J. Am. Chem. Soc. 2021, 143, 45, 19067–19077
56. Functionalized wood with tunable tribopolarity for efficient triboelectric nanogenerators. Sun, J.; Tu, K.; Büchele, S.; MarieKoch, S.; Ding, Y.; Ramakrishna, S. N.; Stucki, S.; Guo, H.; Wu, C.; Keplinger, T.; Pérez-Ramírez, J.; Burgert, I.; Panzarasa, G. Matter 2021, 4, 3049–3066.
55. Effect of Internal Architecture on the Assembly of Soft Particles at Fluid Interfaces. Vialetto, J.; Camerin, F.; Grillo, F.; Ramakrishna, S. N.; Rovigatti, L.; Zaccarelli, E.; Isa, L. ACS Nano 2021, 15, 8, 13105–13117.
54. KAT Ligation for Rapid and Facile Covalent Attachment of Biomolecules to Surfaces. Fracassi, A.; Ray, A.; Nakatsuka, N.; Passiu, C.; Tanriver, M.; Schauenburg, D.; Scherrer, S.; Chaib, A. O.; Mandal, J.; Ramakrishna, S. N.; Bode, J. W.; Spencer, N. D.; Rossi, A.; Yamakoshi, Y. ACS Appl. Mater. Interfaces 2021, 13, 24.
53. Exploring the roles of roughness, friction and adhesion in discontinuous shear thickening by means of thermo-responsive particles. Hsu, C.P.; Mandal, J.; Ramakrishna, S.N.; Spencer, N. D.; Isa, L. Nature Communications. 2021, 12 (1), 1–10.
52. Magnetic propulsion of colloidal microrollers controlled by electrically modulated friction. Demirörs, A. F.; Stauffer, A.; Lauener, C.; Cossu, J.; Ramakrishna, S.N.; de Graaf, J.; Alcantara, C. C. J.; Pané, S.; Spencer, N. D.; Studart, A. R. Soft Matter, 2021, 17, 1037-1047.
51. Topology and Molecular Architecture of Polyelectrolytes Determine Their pH-Responsiveness When Assembled on Surfaces. Trachsel, L.; Ramakrishna, S.N.; Romio, M.; Spencer, N. D.; Benetti, E. M. ACS Macro Lett. 2021, 10, 1, 90–97.
2020
50. Polymer Topology Determines the Formation of Protein Corona on Core–Shell Nanoparticles. Schroffenegger, M.; Leitner,N.S.; Morgese, G,; Ramakrishna, S.N.; Willinger, M.; Benetti, E. M and Reimhult, E. ACS nano. 2020, 14 (10), 12708-12718.
49. Single-Molecule AFM Study of DNA Damage by 1O2 Generated from Photoexcited C60. Ray, A.; Liosi, K.; Ramakrishna, S.N.; Spencer, N. D.; Kuzuya. A.; Yamakoshi. Y. J. Phys. Chem. Lett. 2020, 11, 18, 7819–7826
48. Fabrication of Biopassive Surfaces Using Poly(2‐alkyl‐2‐oxazoline)s: Recent Progresses and Applications. Trachsel, L.; Romio, M.; Ramakrishna, S.N.; Benetti, E. M. Adv. Mater. Interfaces, 2020, 2000943.
47. Functional Nanoassemblies of Cyclic Polymers Show Amplified Responsiveness and Enhanced Protein-Binding Ability. Trachsel, L.; Romio, M.; Grob, B.; Zenobi-Wong, M.; Spencer, N. D.; Ramakrishna, S.N*.; Benetti, E. M*. ACS Nano. 2020, 14, 8, 10054–10067.
46. Topological Polymer Chemistry Enters Materials Science: Expanding the Applicability of Cyclic Polymers. Romio, M.; Trachsel, L.; Morgese, G,; Ramakrishna, S.N.; Spencer, N. D.; Benetti, E. M. ACS Macro Lett. 2020, 9, 7, 1024–1033.
45. Probing the frictional properties of soft materials at the nanoscale. Liamas, E.; Connell, S.D.; Ramakrishna, S.N.; Sarkar, A. Nanoscale, 2020, 12, 2292-2308 (review article)
2019
44. Bioinert and Lubricious Surfaces by Macromolecular Design. Yan, W.; Ramakrishna, S.N.; Romio, M.; Benetti, E. M. Langmuir, 2019, 35 (42), 13521-13535 (review article)
43. Load and velocity dependence of friction mediated by dynamics of interfacial contacts. Ouyang. W.; Ramakrishna, S.N*.; Rossi, A.; Urbakh. M.; Spencer, N. D.; Arcifa, A* Phys. Rev. Lett. 2019, 123, 116102.
42. Brushes, Graft-Copolymers or Bottlebrushes? The Effect of Polymer Architecture on the Nanotribological Properties of Grafted-From Assemblies. Yan, W.; Ramakrishna, S.N.; Spencer, N. D.; Benetti, E. M. Langmuir, 2019, 35, 35, 11255-11264.
41. Growing Polymer Brushes from a Variety of Substrates under Ambient Conditions by Cu0-Mediated Surface-Initiated ATRP. Yan, W.; Fantin, M.; Ramakrishna, S.N.; Spencer, N. D.; Matyjaszewski, K.; Benetti, E. M. ACS Appl. Mater. Interfaces 2019, 11, 30.
40. Facile tuning of the mechanical properties of a biocompatible soft material. Vigolo, D.; Ramakrishna, S.N.; deMello, A. J. Scientific Reports, 2019 9(1), p7125.
39. Indenting polymer brushes of varying grafting density in a viscous fluid: A gradient approach to understanding fluid confinement. Mathis, C.H.; Simic.R.; Kang, C.; Ramakrishna, S.N.; Isa, L.; Spencer, N. D. Polymer, 2019, 169, 115-123.
38. Comb-like Polymers with Topologically Different Side Chains for Surface Modification: Assembly Process and Interfacial Physicochemical Properties. Ramakrishna, S.N*.;Morgese, G.; Zenobi-Wong, M.; Benetti, E. M*. Macromolecules. Macromolecules, 2019, 52 (4), pp 1632–1641.
37. Surface-grafted assemblies of cyclic polymers: Shifting between high friction and extreme lubricity. Divandari, M.; Gombert.; V.; Ramakrishna, S.N* and Benetti, E. M* European Polymer Journal110 (2019) 301–306.
2018
36. Surface Density Variation within Cyclic Polymer Brushes Reveals Topology Effects on their Nanotribological and Biopassive Properties. Divandari, M.; Trachsel, L.; Yan, W.; Rosenboom, J.; Spencer, N. D.; Zenobi-Wong, M.; Morgese, G*.; Ramakrishna, S.N*and Benetti, E. M*. ACS Macro Lett, 2018, 7, pp 1455–1460.
35. Mixing PEG and Poly(2-Alkyl-2-Oxazoline)s Enhances Hydration and Viscoelasticity of Polymer Brushes and Determines Their Nanotribological and Antifouling Properties. Morgese, G.; Gombert.; V.; Ramakrishna, S.N*and Benetti, E. M*. ACS Applied Materials and Interfaces, 2018. 10 (48), pp 41839–41848.
34. Correlating diameter, mechanical and structural properties of poly(L-lactide) fibres from needleless electrospinning. Morel, A.; Domaschke ,S; Urundolil Kumaran, V.; Alexeev, D.; Sadeghpour, A.; Ramakrishna, S.N.; Ferguson, S.J.; Rossia, R.M.; Mazzab, E.; Ehret, A.E.; Fortunatoa, G. Acta Biomater, 81 (2018) 169–183.
33. The Role of Cu0 in Surface-Initiated Atom Transfer Radical Polymerization: Tuning Catalyst Dissolution for Tailoring Polymer Interfaces. Fantin, M.; Ramakrishna, S.N.; Yan, J.; Yan, W.; Divandari, M.; Spencer, N. D.; Matyjaszewski, K.; Benetti, E. M. 2018. Macromolecules, 2018, 51 (17), pp 6825–6835
32. Chemical Design of Non-Ionic Polymer Brushes as Biointerfaces: Poly(2-oxazine)s Outperform both Poly(2-oxazoline)s and PEG. Morgese, G.; Verbraeken, B.; Ramakrishna, S.N.; Gombert.; V.; Cavalli, E.; Rosenboom, J.; Zenobi-Wong, M.; Spencer, N. D.; Hoogenboom, R.; .; Benetti, E. M. 2018. Ang. Chem. Int.Ed.2018, 57,1–7
31. Roughness-Dependent Tribology Effects on Discontinuous Shear Thickening. Hsu, C.P.; Ramakrishna, S.N.; Zanini, M.; Spencer, N. D.; Isa, L. 2018. PNAS. 2018; 115(20) pp 5117-5122.
30. Design and Characterization of Ultrastable, Biopassive and Lubricious Cyclic Poly(2-alkyl-2-oxazoline) Brushes. Yan, W.; Divandari, M.; Rosenboom, J.; Ramakrishna, S.N.; Morgese, G.; Benetti, E. M. Polym. Chem,2018,9, 2580-2589
29. Lubrication of Si-Based Tribopairs with a Hydrophobic Ionic Liquid: The Multiscale Influence of Water. Arcifa, A.; Rossi,A.; Ramakrishna, S.N.; Espinosa-Marzal, R. M.; Sheehan, S.; Spencer, N. D.; 2018. J. Phys. Chem. C,2018, 122 (13), pp 7331–7343.
28. Engineering Lubricious, Biopassive Polymer Brushes by Surface-Confined, Controlled Radical Polymerization. Dehghani, E. S.; Ramakrishna, S.N*.; Spencer, N. D.; Benetti, E. M*. 2018. Ind. Eng. Chem. Res.2018, 57 (13), pp 4600–4606.
2017
27. Understanding Complex Tribofilms by Means of H3BO3-B2O3 Model Glasses. Spadaro, F.; Rossi, A.; Ramakrishna, S.N.; Lainé, E.; Woodward, P and Spencer. N. D. 2017. Langmuir. 2018, 34 (6), pp 2219–2234
26. Hairy and Slippery Polyoxazoline-Based Copolymers on Model and Cartilage Surfaces. Morgese, G.; Ramakrishna, S.N.; Simic.R.; Zenobi-Wong, M.; Benetti, E.M. Biomacromolecules. 2018, 19 (2), pp 680–690
25. Effects of Lateral Deformation by Thermoresponsive Polymer Brushes on the Measured Friction Forces. Ramakrishna, S.N*.; Cirelli, M.; Divandari, M.; Benetti*, E. M. Langmuir. 2017, 33 (17), 4164–4171.
24. Loops and Cycles at Surfaces: The Unique Properties of Topological Polymer Brushes. Benetti, E. M.; Divandari, M.; Ramakrishna, S.N.; Morgese, G.; Yan.W.; Trachsel, L. Chemistry - A European Journal.2017, 23(51), 12433–12442. (review article)
22. Next-Generation Polymer Shells for Inorganic Nanoparticles are Highly Compact, Ultra-Dense, and Long-Lasting Cyclic Brushes. Morgese, G.; Shirmardi Shaghasemi, B.; Causin, V.; Zenobi Wong, M.; Ramakrishna, S. N.; Reimhult, E.; & Benetti, E. M. Ang. Chem. Int.Ed.2017, 56, 4507-4511
21. Fabrication and Interfacial Properties of Polymer Brush Gradients by Surface-Initiated Cu(0)-Mediated Controlled Radical Polymerization. Dehghani, E. S.; Yunhao, D.; Zhang.T.; Ramakrishna, S.N.; Spencer, N.D.; Jordan.R.; Benetti, E. M. Macromolecules. 2017, 50 (6), pp 2436–2446
20. Controlled Crosslinking is a Tool to Precisely Modulate the Nanomechanical and Nanotribological Properties of Polymer Brushes. Dehghani, E. S.; Ramakrishna, S.N.; Spencer, N.D and Benetti, E. M. Macromolecules. 2017, 50 (7), pp 2932–2941
19. Gradient Nanocomposite Printing by Dip Pen Nanolithography. Kandemir,A.C.; Ramakrishna, S.N.; Erdem,D.; Courty,D.;Spolenak,R. Composites Science and Technology.2017, 138, 186-200.
2016
18. Topological Polymer Chemistry Enters Surface Science: Linear vs Cyclic Polymer Brushes. Morgese,G.; Trachsel, L.; Romio,M., Divandari, M.; Ramakrishna, S.Nand Benetti, E. M. Ang. Chem. Int.Ed. 2016, 55(50), 15583–15588
17. Crosslinking Polymer Brushes with Ethylene Glycol-Containing Segments: Influence on Physicochemical and Antifouling Properties. Dehghani, E. S.; Spencer, N. D.; Ramakrishna, S. N.; Benetti, E. M. Langmuir. 2016, 32(40), 10317–10327.
16. Understanding the effect of hydrophobic protecting blocks on the stability and biopassivity of polymer brushes in aqueous environments: A Tiramisù for cell-culture applications. Divandari. M., Dehghani.E., Ramakrishna, S. N., Spencer, N.D and Benetti, E. M. Polymer. 2016, 98, 470–480.
15. Layering of Ionic liquids on rough surfaces. Sheehan A, L. Andres Jurado.; Ramakrishna, S. N.; Arcifa. A .; Rossi. A.;. Spencer. N.D and Espinosa-Marzal, R. M. Nanoscale. 2016. 8.4094-2106
14. Stem-Cells Clinging by a Thread: AFM Measure of Polymer-Brush Lateral Deformation. Gunnewiek,M.K.; Ramakrishna, S. N.; Andrea di Luca, G. Vancso, J.; Moroni,L and Benetti, E. M., Adv. Mater. Interfaces. 2016, 3, 1500456.
2015
13. Lateral Deformability of Polymer Brushes by AFM-Based Method. Polymer and colloid highlights. Ramakrishna, S. Nand Benetti, E. M.; CHIMIA. 2015, 69, 11.
12. An Intensive Short Course on Atomic-Force Microscopy. Burnham, N. A.; Arcifa, A.; Divandari, M.; Mathis, C.;Ramakrishna, S. N and Spencer.N.D. Advanced labs. BFY II Proceedings. 2015.
11. Amplified Responsiveness of Multilayered Polymer Grafts: Synergy Between Brushes and Hydrogels. Ramakrishna, S. N.; Cirelli, M.; Kooij, E. S.; Klein Gunnewiek, M.; Benetti, E. M. Macromolecules. 2015, 48 (19), pp 7106–7116
10. Ultrathin, Freestanding, Stimuli-Responsive, Porous Membranes from Polymer Hydrogel-Brushes. Kang, C.; Ramakrishna, S. N.; Nelson, A.; Cremmel, C. V. M.; Stein, Vom, H.; Spencer, N. D.; Isa, L.; Benetti, E. M. Nanoscale. 2015, 7, 13017 – 13025,
9. Versatile method for AFM-tip functionalization with biomolecules: fishing a ligand by means of an in situ click reaction. 2015, Kumar.R, Ramakrishna.S.N, Naik, V.;,Chu.Z.;Drew.E.M.; Spencer.N.D, and Yamakoshi.Y. Nanoscale,7,6599-6606 (*co-first author)
2014
8. Stratified Polymer Grafts: Synthesis and Characterization of Layered ‘Brush’ and ‘Gel’ Structures. Li,A.;Ramakrishna, S.N.; Nalam, P.C.; Edmondo M. Benetti.; Spencer,N.D. Adv. Mater. Interfaces. 2014, 1, 1300007
2013
7. Adhesion and Friction Properties of Polymer Brushes Coated on Rough Surfaces: A Gradient Approach. Ramakrishna, S. N.; Espinosa-Marzal, R. M.; Naik, V.; Nalam, P.C.;Spencer, N. D. Langmuir. 2013, 29 (49), pp 15251–15259.
6. Nano-mechanical characterization of polymer brushes in viscous aqueous solvent mixtures. 2013, Nalam, P.C.; Ramakrishna, S. N.; Espinosa-Marzal, R. M.; Spencer, N. D. Langmuir, 29(32), pp 10149-10158.
5. Tuning Surface Mechanical Properties by Amplified Polyelectrolyte Self-Assembly: Where ‘Grafting-From’ Meets ‘Grafting-To’. Li,A.; Ramakrishna, S.N.; Tobias Schwarz,; Edmondo M. Benetti.; Spencer.N.D. ACS Appl. Mater. Interfaces. 2013, 5 (11), pp 4913–4920.
4. Rubber friction with surfaces patterned with rigid spherical asperities. Nguyen, D.T.; Ramakrishna, S.N.; Fretigny, C.; Spencer N.D.; Chenadec, Y.L.; Chateauminois. A. Tribology Letters. 2013, 49 (1), 135-144.
3. Study of adhesion and friction properties on a nanoparticle gradient surface: Transition from JKR to DMT contact mechanics. Ramakrishna, S. N.; Nalam, P.C.; Clasohm, L. Y.; Spencer, N. D. Langmuir. 2013, 29 (1), 175–182.
2012
2. Poly(acrylamide) films at the solvent-induced glass transition: adhesion, tribology, and the influence of crosslinking. Li, A.; Ramakrishna, S. N.; Kooij, E. S.;, Espinosa-Marzal, R. M.; Spencer, N. D. Soft Matter. 2012, 8, 9092-9100.
2011
1. Controlling adhesion force by means of nanoscale surface roughness. Ramakrishna, S. N.; Clasohm, L. Y.; Rao, A.; Spencer, N. D. Langmuir. 2011, 27, 9972-9978.