Investigation of size effect through in-situ SEM testing of polystyrene micropillars

Thimmappa Shetty Guruprasad, Shantanu Bhattacharya, Sumit Basu

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Size effects in micron sized pillars loaded in compression, fabricated out of metal single crystals with FIB milling has been reported by several authors. The size effect manifests in a significant amplification of the flow stress with decrease in diameter. Amorphous glassy polymers are widely used in micro-structures, such as in many micro-electro-mechanical system (MEMS) based devices in electronics and biological applications. But their mechanical behaviours at these length scales have not been adequately explored. In this work, we show that micropillars of an amorphous material, polystyrene (PS), also exhibit significant size effects under compression. The pillars are fabricated by methods that do not involve focused ion beam (FIB) milling and are therefore, free of ion damage. Micropillars of diameters ranging from 38 to 190 μm have been fabricated using a microfabrication technique and they are deformed in-situ in a FESEM under compression. The stress strain plots are obtained by fitting the load displacement behaviour using well calibrated constitutive model. Results suggest that the yield stress of PS intrinsically depend on the diameter.

Original languageEnglish
Title of host publicationMicro and Nanomechanics - Proceedings of the 2016 Annual Conference on Experimental and Applied Mechanics
EditorsNikhil Karanjgaokar, La Vern Starman, Jennifer Hay
PublisherSpringer New York LLC
Number of pages7
ISBN (Print)9783319422275
Publication statusPublished - 2017
EventAnnual Conference and Exposition on Experimental and Applied Mechanics, 2016 - Orlando, United States
Duration: 06-06-201609-06-2016

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652


ConferenceAnnual Conference and Exposition on Experimental and Applied Mechanics, 2016
Country/TerritoryUnited States

All Science Journal Classification (ASJC) codes

  • Engineering(all)
  • Computational Mechanics
  • Mechanical Engineering


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