1. Relaxation Dynamics and Soft Elasticity of Main-Chain Liquid Crystal Elastomers, S. Kumar, S. Dey, D.M Agra-Kooijman, Invited Talk,  7th International Liquid Crystal Elastomer Conference, Shanghai, P. R. China, 10-12 Sept. (2013).

2. Revisiting the Structure of Mesophases of Chromonic Systems, S. Kumar, D.M. Agra-Kooijman, and G. Singh, Invited Talk, 19th National Conference on Liquid Crystals, Thapar University, Patiala, India, Nov. 21-23 (2012).

3. Structure of and molecular organization in the de Vries smectic-A and -C phases, S. Kumar, Invited Talk, 4th Workshop on Liquid Crystals for Photonics, Hong Kong University of Science and Technology, Hong Kong, December 9-11 (2012).

4. Submolecular Organization in de Vries Smectic-A and –C Phases, H.-G. Yoon, D. M. Agra-Kooijman, K. Ayub, R. P Lemieux, and  S. Kumar, Keynote Speech at the 18th International Conference on Liquid Crystals, Itanagar, India, November 15-17 (2011).

5. What are Cybotactic Groups, Swarms, Clusters, Correlated Regions, and Pretransitional Fluctuations? D. M. Agra-Kooijman, H.G. Yoon and S. Kumar, Plenary Talk at the workshop on Soft Matter Chemistry, Bangalore, India, November 9-11 (2011).

6. Diffuse Cone Behavior and Microscopic Structure of the de Vries Smectic-A and Smectic-C Phases, S. Kumar, Invited Talk at the 15th Liquid Crystal Conference - SPIE Annual Symposium, Diego, August 21 - 25 (2011).

7. Microstructure of de Vries Smectic Phases, S. Kumar, Plenary Talk at the 2nd International Symposium on Liquid Crystals: Science and Technology, Changzhou, China, 17–19 July (2011).

8. Improvised X-ray Diffraction Methods to Investigate Structures of Soft Pharmaceutical Formulations and Intermediates, S. Kumar, Invited Talk at the 13th the International Workshop on Physical Characterization of Pharmaceutical Solids, Indianapolis, IN, June 20-23 (2011).

9. Cybotactic groups, Swarms, Clusters, Correlated Regions, and Pretransitional Fluctuations in Clamatic and Bent-Core Mesogens, D. M. Agra-Kooijman, H.G. Yoon, and S. Kumar, Invited Talk, 23rd International Liquid Crystal Conference, Krakow, Poland, July 11-16 (2010)

10. Strain and Temperature Dependence of Liquid Crystalline Order in Elastomers, D.M. Agra-Kooijman, S. Dey, L. Joshi, and S. Kumar, 16th National LC Conference, Lucknow, India, Oct. 26-28 (2009).

11. Unusual Supramolecular Associations of Phasmidic Type Carboxylic Acid: Formation of Bent-core Dimeric Mesogen and Its Mesophasic Behaviors S.-W. Kang, S.-Y. Jeong, S. Kumar, V. Prasad, S. K. Varshney, International Symposium on Biaxial Nematic Liquid Crystals, Kent, OH, October 27-28 (2008).

12. Evolution of Self-organized Aggregates in Chromonic Liquid Crystal Phases of Aqueous Solutions of Sunset Yellow, L. Joshi, S.-W. Kang, and S. Kumar, 15th National Liquid Crystal Conference, Indian Institute of Science, Bangalore, India, Oct. 13-15 (2008).

13. Liquid Crystals: Optical Properties and Light Driven Effects, S. Kumar, Keynote Speech, Light Controlled Liquid Crystalline Complex Adaptive Materials, LC2CAM, Boulder, Aug. 7-10 (2008).

14. Thermotropic Biaxial Nematic Phase of Bent-Core and Tetrapodic Mesogens, S. Kumar, S.-W. Kang, B. R. Acharya, V. Prasad, G. Mehl, and S. Sprunt, 22nd International Liquid Crystal Conference, Jeju Island, S. Korea, June 24-Jul 4 (2008).

15. Recent Breakthroughs and Exiting Future of Liquid Crystal Research and Technology, S. Kumar, Keynote Speech, 14th National Liquid Crystal Conference, Siliguri, India, Dec. 17-19 (2007).

16. Recent Development in Thermotropic Biaxial Nematic Phases, S. Kumar, 12th International Topical Meeting on Optics of Liquid Crystals, Pueblo, Mexico, Oct 1-5 (2007).

17. Thermotropic Biaxial Nematic Phase in Bent-Core and Tetrapodic Mesogens, S. Kumar, Gordon Research Conference on Liquid Crystals, Colby-Sawyer College, New London, NH, June 10-15 (2007).

18. From Ideas to Funding: How to Write Successful Proposals to NSF, S. Kumar, University of Missouri, Columbia, MO, May 21 (2007).

19. Surface Morphology and its Effect on Liquid Crystal Alignment, S. Kumar, Ohio Nanosummit, Akron, OH, April 23-25 (2007).

20. New Found Thermotropic Biaxial Nematic Phase, Plenary Talk, S. Kumar, International Conference on Liquid Crystals, Dec. 5-8 (2006), Mumbai University, India

21. Polymers in Display Applications, S. Kumar and S.W. Kang, TopCon 2006: Recent Advances in Organic and Polymer Display Technologies. Akron, OH, October 23-24, (2006).

22. More examples of the biaxial nematic phase, S. Kumar, 2nd International Symposium on Biaxial Nematics, Southampton, UK, Jan 27 (2006).

23. Liquid Crystal Alignment on Solid Substrates, S. Kumar, IMID'05, Seoul, S. Korea, July 19-22 (2005).

24. Display and Non-display Applications of the Phase Separated Composite Films Method, S. Kumar, 33rd Topical Meeting on Liquid Crystals, Paderborn Germany, March 16-18 (2005).

25. The Discovery of the Biaxial Nematic Phase in Bent-Core Mesogens and Possible Technological Applications, S. Kumar, International Meeting on Information Display 2004, Daegu, S. Korea, August 22 (2004).

26. Uniaxial and Biaxial Nematic Phases in Bent-Core Mesogens, Plenary Talk, S. Kumar, Conference on Disorder, Complexity and Biology, Banaras Hindu University, Varanasi, India, July 12-15 (2004).

27. The discovery of biaxial nematic phase in bent-core mesogens and possible technological applications, B. R. Acharya, A. Primak and S. Kumar, International Meeting on Information Display, Dague, S. Korea, August 23-26, (2004).

28. Thermotropic Biaxial Nematic Phase in Banana Liquid Crystals, B. Acharya, A. Primak, and S. Kumar, 20th International Liquid Crystal Conference, Ljubljana, Slovenia, July 4-9 (2004).

29. Phase-Separated Composite Films for Flexible Liquid Crystal Displays, S. Kumar, Great Lakes Photonics Symposium, June, 7-11 (2004).

30. Self-assembled Structures in Pharmaceutically-relevant Systems, S. Kumar, Workshop on Pharmaceutical Applications of Synchrotron Radiation, Brookhaven National Laboratory, May 17-19 (2004).

31. Temperature Dependence of the Smectic-A Layer Spacing and its Effect on Layer Defects in the SmC* Phase, C.Wang, P.J.Bos, S. Kumar, M.Wand, M. Handschy, Tohoku University 21st Century COE Program, Jan 28-30, Sendai, Japan, (2004).

32. Different Limits of Phase Separation and Their Applications, Q. Wang, B. Acharya, H.-C. Choi, J.-H. Kim, and S. Kumar, SPIE Meeting, Santa Clara, Januray 20-24, (2003), Technical Program and Summary Digest, Paper 5003-12 (S4), page 88 (2003).

33. The Thermotropic Biaxial Nematic Phase, S. Kumar, The Thermotropic Biaxial Nematic Phase, S. Kumar, Conference on Liquid Crystals and Other Soft Materials, Raman Research Institute, Bangalore, India, December, 18-20 (2002).

34. Different Shades and Shapes of Phase Separation and Their Applications, S. Kumar, Workshop on Phase Separated Composites and Networks, Seoul National University, August 20 (2002).

35. The Old Phase Separation Method and Its New Limits, Plenary Talk, S. Kumar, 2nd International Meeting on Information Display, Daegu, Korea, August 21 (2002).

36. Exploiting New Regime of Phase Separation for the Fabrication of Sub-micron Photonic Liquid Crystal Devices, S. Kumar, 5th Ibero-American Workshop on Complex Fluids and Their Applications, Maringa, Brazil, September 9-12 (2001).

37. Phase Separated Composite LC Flexible Devices with and without Alignment Layers, S. Kumar, 2001 International Meeting on Information Display, Deagu, S. Korea, August 29-31 (2001). Selected for an award by the Ministry of Science and Technology of S. Korea as the best contribution to LC application field.

38. Bent-core Liquid Crystals: Novel Smectic and Biaxial Nematic Phases, S. Kumar, 2001 International Meeting on Information Display, Deagu, S. Korea, August 29-31 (2001).

39. Effect of Phase Separation on Electro-optical Characteristics of Ferroelectric Liquid Crystals, S. Kumar, International Ferroelectric Liquid Crystal Conference, Washington, D.C., August 4-9 (2001).

40. Using Phase Separation to fabricate New Generation of Electro-optical and Photonic Microdevices, S. Kumar, India and Abroad Conference, S. N. Bose Institute, Calcutta, India, Jan. 2-3 (2001).

41. LC Devices Fabricated with Phase Separated Composite Structures Method using Flexible and Rigid Substrates, S. Kumar, Liquid Crystal International Summer School 2000 on Next Generation of Liquid Crystal Displays, Kon-Kuk University, Korea, July 21 (2000).

42. Beam steering and optical micro-devices built with a new phase separation method, S. Kumar, ALCOM Symposium on Optical Beam Steering, June 29-30, (2000).

43. What really aligns Liquid Crystals on Solid Substrates?, S. Kumar, Workshop on Alignment of Ferroelectric Liquid Crystals, Boulder, CO, May 21-23 (2000).

44. Electrically Controllable Liquid Crystal Microdevices Based on Phase Separated Composite Films Method, S. Kumar, 4th Annual Symposium on the Physics of Soft Materials, LRSM, University of Pennsylvania, Philadelphia, Oct. 9, (1999).

45. Liquid Crystal Devices and Electrically Controllable Optical Microstructures Prepared by Phase Separated Composite Films Method, S. Kumar, Gordon Research Conference on Liquid Crystals, Tilton School, Tilton, NH, June 6-11 (1999).

46. Electro-optical Properties of Phase Separated Composite Films of Polymer and Liquid Crystal, S. Kumar, APS March Meeting, Atlanta, GA, March 20-26, Bull. Am. Phys. Soc. 44, 1676 (1999).

47. Phase Separated Composite Films of Liquid Crystals, Golden Jubilee Discussion Meeting on Liquid Crystals and Other Soft Materials, S. Kumar, Raman Research Institute, Bangalore, December 28-31, (1998).

48. Ferroelectric and Antiferroelectric LC Displays Based on Phase Separated Film Method, V. Vorflusev and S. Kumar, 7th International SID Symposium on Advanced Display Technologies, Dec. 1-5 (1998), Minsk, Belarus.

49. Phase Separated Composite Organic Film (PSCOF) Liquid Crystal Displays, S. Kumar, 17th International Liquid Crystal Conference, Strasbourg, France, July 19-24, (1998).

50. Electro-optical Effects in Phase Separated Composite Films of Ferroelectric Liquid Crystal and Polymer, S. Kumar, International Conference on Composites Engineering. Las Vegas, July 5-10 (1998).

51. Study of Linear-photopolymerized alignment layers by x-ray reflectivity and atomic force microscopy, S. Kumar, Gordon Research conference on Liquid Crystals, Tilton, NH, June 8-13 (1997).

52. Lyotropic Liquid Crystal under Simple and Oscillatory Shear, J. T. Mang, S. Kumar, and B. Hammouda, 16th International Liquid Crystal Conference, Kent, OH, June 24-28 (1996).

53. Longitudinal Ferroelectric Liquid Crystals: Attempts and Successes, S. Kumar, Indo-US symposium on Liquid Crystals, Bangalore, India, Jan 2-5 (1996).

54. Thin Liquid Crystal films and Alignment Layers, S. Kumar, 4th International Conference on Advanced Materials, Cancun, Mexico, August 27-September 1 (1995).

55. X-ray Reflectivity Study of Thin LC films, S. Kumar, 4th International Conference on Surface X-ray and Neutron Scattering, Lake Geneva, WI, June 26-30 (1995).

56. X-ray Diffraction and Calorimetric Studies of Nematic - Nematic and Smectic - Smectic Phase Transitions, G. Nounesis, Y. Shi and S. Kumar, ACS Meeting, Anaheim, CA, April 2-7 (1995).

57. Structure of Thin LC Films and Alignment Layers, S. Kumar, B. Cull, Y. Shi, and M Schadt, ACS Meeting, Anaheim, CA, April 2-7 (1995).

58. SANS Study of Side Chain Polymer and Lyotropic Liquid Crystals, S. Kumar, J. T. Mang, T. P. Rieker, P. A. Seeger, American Crystallographic Association's Annual Meeting, Albuquerque, NM, May 23-28 (1993).

59. Small Angle Neutron Scattering Study of Conformational Anisotropy in Side Chain Polymer Liquid Crystals, J. T. Mang, T. P. Rieker, P. Patel, and S. Kumar, American Chemical Society Symposium on Neutron Scattering from Polymers, 204th ACS National Meeting, Washington, D. C., August 23-28 (1992).

60. The Case of the Missing Incommensurate Smectic-A Phases, S. Kumar, Bull. Am. Phys. Soc. 37, 216 (1992); American Physical Society Meeting, March 16-20, Indianapolis, IN.

61. Do Incommensurate Smectic-A Phases Exist? S. Kumar, Gordon Research Conference on Liquid Crystals, Wolfeboro, NH, June 17-22 (1991).

62. Phase Transitions in Micellar Liquid Crystals, S. Kumar, 6th International Symposium on Surfactant in Solutions, August 18-22 (1986), New Delhi, India.

Plenary and Invited