# Hierarchical helical nanofiber assembly ## expand\_more #### Hierarchical Helical Nanofiber Assembly Inspired by biological examples of highly controlled nanofiber self-organization, such as the clustering of beetles’ tarsi, our group has pioneered the use of self-assembling synthetic nanofibers to generate previously unseen structures with unique helical patterns and hierarchical order. The structures are created using only a uniform periodic array of nanofibers and an evaporating liquid to provide a bending force; by varying the geometric, mechanical, and surface properties of the fibers, we have developed a model describing conditions that favor hierarchical self-assembly into bundles, and bundles of bundles, with helicity arising spontaneously as pillars and bundles twist around each other. The chirality, shape, and size of the assembled structures are all highly sensitive to the delicate balance of elastic, capillary, and adhesive forces between adjacent fibers. In particular, we have discovered that surface adhesion after the system dries is a central player in several respects: chirality arises only if the adhesion is weak enough to allow touching fibers to slip relative to each other, and structures can undergo steps of hierarchical disassembly to arrive at sizes determined by the adhesion strength. We are exploring and modeling in detail how the dynamic interplay among all forces in the system gives rise to this fascinating assortment of structures, and how these forces can be harnessed to generate a variety of tunable chiral patterns at larger scales. ## Publications Download 5 citations download- [BibTeX](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=bibtex) - [EndNote X3 XML](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=endnote8) - [EndNote 7 XML](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=endnote7) - [Endnote tagged](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=tagged) - [Marc](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=marc) - [PubMedId](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=pubmed_id) - [RIS](/bibcite/export?pager_style=standard_pager&number_of_items=15&sort_field=bibcite_year--desc&taxonomy_filters%5Bfield_hwp_c_researchtopics12%5D%5B0%5D%5Btarget_id%5D=106131&taxonomy_filters%5Bfield_hwp_c_project%5D%5B0%5D%5Btarget_id%5D=111581&&&format=ris) ### 2012 Grinthal A, Kang SH, Epstein AK, Aizenberg M, Khan M, Aizenberg J. [Steering nanofibers: An integrative approach to bio-inspired fiber fabrication and assembly](/publications/steering-nanofibers-integrative-approach-bio-inspired-fiber-fabrication-and-assembly). Nano Today. 2012;7(1):35–52. doi:10.1016/j.nantod.2011.12.005 Grinthal A, Kang SH, Epstein AK, Aizenberg M, Khan M, Aizenberg J. [Steering nanofibers: An integrative approach to bio-inspired fiber fabrication and assembly](/publications/steering-nanofibers-integrative-approach-bio-inspired-fiber-fabrication-and-assembly). Nano Today. 2012;7(1):35–52. doi:10.1016/j.nantod.2011.12.005 - [ picture\_as\_pdf2012\_NanoToday\_review.pdf](/sites/g/files/omnuum6296/files/2012_NanoToday_review_0.pdf) - [ picture\_as\_pdf2012\_NanoToday\_review.pdf](/sites/g/files/omnuum6296/files/2012_NanoToday_review_0.pdf) ### 2011 Kang SH, Wu N, Grinthal A, Aizenberg J. [Meniscus Lithography: Evaporation-Induced Self-Organization of Pillar Arrays into Moire Patterns](/publications/meniscus-lithography-evaporation-induced-self-organization-pillar-arrays-moire-patterns). Phys. Rev. Lett. 2011;107(17):177802. doi:10.1103/PhysRevLett.107.177802 Kang SH, Wu N, Grinthal A, Aizenberg J. [Meniscus Lithography: Evaporation-Induced Self-Organization of Pillar Arrays into Moire Patterns](/publications/meniscus-lithography-evaporation-induced-self-organization-pillar-arrays-moire-patterns). Phys. Rev. Lett. 2011;107(17):177802. doi:10.1103/PhysRevLett.107.177802 - [ picture\_as\_pdfPRL\_2011.pdf](/sites/g/files/omnuum6296/files/PRL_2011_0.pdf) - [ picture\_as\_pdfPRL\_2011.pdf](/sites/g/files/omnuum6296/files/PRL_2011_0.pdf) ### 2010 Paulose J, Nelson DR, Aizenberg J. [Two-parameter sequential adsorption model applied to microfiber clustering](/publications/two-parameter-sequential-adsorption-model-applied-microfiber-clustering). Soft Matter,. 2010;6:2421–2434. Paulose J, Nelson DR, Aizenberg J. [Two-parameter sequential adsorption model applied to microfiber clustering](/publications/two-parameter-sequential-adsorption-model-applied-microfiber-clustering). Soft Matter,. 2010;6:2421–2434. - [ picture\_as\_pdf2010\_SoftMatter\_Paulose.p...](/sites/g/files/omnuum6296/files/2010_SoftMatter_Paulose_0.pdf) - [ picture\_as\_pdf2010\_SoftMatter\_Paulose.p...](/sites/g/files/omnuum6296/files/2010_SoftMatter_Paulose_0.pdf) Kang SH, Pokroy B, Mahadevan L, Aizenberg J. [Control of Shape and Size of Nanopillar Assembly by Adhesion-Mediated Elastocapillary Interaction.](/publications/control-shape-and-size-nanopillar-assembly-adhesion-mediated-elastocapillary) ACS Nano. 2010;4(11):6323–6331. doi:10.1021/nn102260t Kang SH, Pokroy B, Mahadevan L, Aizenberg J. [Control of Shape and Size of Nanopillar Assembly by Adhesion-Mediated Elastocapillary Interaction.](/publications/control-shape-and-size-nanopillar-assembly-adhesion-mediated-elastocapillary) ACS Nano. 2010;4(11):6323–6331. doi:10.1021/nn102260t - [ picture\_as\_pdf2010\_ACSNano\_SH.pdf](/sites/g/files/omnuum6296/files/2010_ACSNano_SH_0.pdf) - [ picture\_as\_pdf2010\_ACSNano\_SH.pdf](/sites/g/files/omnuum6296/files/2010_ACSNano_SH_0.pdf) ### 2009 Pokroy B, Kang SH, Mahadevan L, Aizenberg J. [Self-Organization of a Mesoscale Bristle into Ordered, Hierarchical Helical Assemblies](/publications/self-organization-mesoscale-bristle-ordered-hierarchical-helical-assemblies). Science. 2009;323:237–240. Pokroy B, Kang SH, Mahadevan L, Aizenberg J. [Self-Organization of a Mesoscale Bristle into Ordered, Hierarchical Helical Assemblies](/publications/self-organization-mesoscale-bristle-ordered-hierarchical-helical-assemblies). Science. 2009;323:237–240. - [ picture\_as\_pdfScience\_2009\_Boaz.pdf](/sites/g/files/omnuum6296/files/Science_2009_Boaz_0.pdf) - [ picture\_as\_pdfScience\_2009\_Boaz.pdf](/sites/g/files/omnuum6296/files/Science_2009_Boaz_0.pdf) ## Media Gallery [### img25\_02.jpg ](/resource/img2502jpg) ![Hierarchical 2](/sites/g/files/omnuum6296/files/styles/hwp_16_9__480x270/public/aizenberg/files/img25_02.jpg?itok=2w0fJwo0) [### hierarchical\_01.jpg ](/resource/hierarchical01jpg) ![Hierarchical 1](/sites/g/files/omnuum6296/files/styles/hwp_16_9__480x270/public/aizenberg/files/hierarchical_01.jpg?itok=98HMTUXa) ## Media Coverage [Researchers control assembly of nanobristles into helical clusters](http://www.seas.harvard.edu/news-events/news-archive/2009/researchers-control-the-assembly-of-nanobristles-into-helical-clusters), Harvard press release, January 8, 2009.