Geometric control of rippling in supported polymer nanolines.

We study the swelling behavior of finlike polymer line gratings supported on a rigid substrate and show that the edge-supported polymer laminae undergo a rippling instability with a well-defined ripple wavelength λ transverse to the plane of the solid supporting substrate and a ripple amplitude that monotonically decreases from its maximum at the free-edge. These ripple patterns develop due to inhomogeneous compressive strains that arise from the geometric constraints that progressively suppress swelling near the supporting substrate where the laminae are clamped. By experimentally examining the influence of swelling strain and pattern geometry on the observed rippling instability, we find that the ripple wavelength λ scales with line width w for sufficiently long gratings, which is consistent with a simple theory. These trends were validated for polymer nanoline test patterns having w between (50 to 250) nm and a height-to-width aspect-ratio in the range 0.5 to 5. Our results suggest that line geometry, rather than material properties, governs the onset of rippling and suggest simple rules for their control.

[1]  W. S. Rasband,et al.  ImageJ: Image processing and analysis in Java , 2012 .

[2]  R. Álvarez-Puebla,et al.  Controlling inter-nanoparticle coupling by wrinkle-assisted assembly , 2011 .

[3]  P. Stroot,et al.  Swelling-induced instabilities in microscale, surface-confined poly(N-isopropylacryamide) hydrogels , 2010 .

[4]  M. Allen,et al.  Microcrimped Collagen Fiber‐Elastin Composites , 2010, Advanced materials.

[5]  L. Mahadevan,et al.  The shape of a long leaf , 2009, Proceedings of the National Academy of Sciences.

[6]  A. Karim,et al.  Capillary instability in nanoimprinted polymer films , 2009 .

[7]  O. Schmidt,et al.  Bending and wrinkling as competing relaxation pathways for strained free-hanging films , 2009, 1206.2875.

[8]  Mukti Aryal,et al.  Stability of HSQ nanolines defined by e-beam lithography for Si nanowire field effect transistors , 2008 .

[9]  S. Bazhenov,et al.  Can deformation of a polymer film with a rigid coating model geophysical processes? , 2007, The European physical journal. E, Soft matter.

[10]  J. Rogers,et al.  Finite deformation mechanics in buckled thin films on compliant supports , 2007, Proceedings of the National Academy of Sciences.

[11]  Ilsoon Lee,et al.  Wrinkle-free nanomechanical film: control and prevention of polymer film buckling. , 2007, Nano letters.

[12]  Wen-Li Wu,et al.  Effect of deprotection extent on swelling and dissolution regimes of thin polymer films. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[13]  Jean-François Lutz,et al.  Point by point comparison of two thermosensitive polymers exhibiting a similar LCST: is the age of poly(NIPAM) over? , 2006, Journal of the American Chemical Society.

[14]  C. Ober,et al.  Recent progress in high resolution lithography , 2006 .

[15]  Leonidas E. Ocola,et al.  Direct-write e-beam patterning of stimuli-responsive hydrogel nanostructures , 2005 .

[16]  An-Bang Wang,et al.  WRINKLING OF A DEBONDED INITIALLY COMPRESSED Si1-XGeX FILM , 2005 .

[17]  刘金明,et al.  IL-13受体α2降低血吸虫病肉芽肿的炎症反应并延长宿主存活时间[英]/Mentink-Kane MM,Cheever AW，Thompson RW，et al//Proc Natl Acad Sci U S A , 2005 .

[18]  A. Boudaoud,et al.  Buckling of swelling gels , 2005, The European physical journal. E, Soft matter.

[19]  Willi Volksen,et al.  A buckling-based metrology for measuring the elastic moduli of polymeric thin films , 2004, Nature materials.

[20]  Curtis W. Frank,et al.  A microfluidic actuator based on thermoresponsive hydrogels , 2003 .

[21]  L. Mahadevan,et al.  Geometry and physics of wrinkling. , 2003, Physical review letters.

[22]  Jianzhong Wu,et al.  Phase behavior of thermally responsive microgel colloids. , 2003, Physical review letters.

[23]  H. Swinney,et al.  Buckling cascades in free sheets , 2002 .

[24]  M. El-Sayed,et al.  Temperature-jump investigations of the kinetics of hydrogel nanoparticle volume phase transitions. , 2001, Journal of the American Chemical Society.

[25]  S. Sabharwal,et al.  Synthesis and swelling characteristics of poly (N-isopropylacrylamide) temperature sensitive hydrogels crosslinked by electron beam irradiation , 2000 .

[26]  Olga V. Lebedeva,et al.  Mechanical buckling instability of thin coatings deposited on soft polymer substrates , 2000 .

[27]  Hiroshi Ito,et al.  Micro- and Nanopatterning Polymers , 1998 .

[28]  Chi Wu,et al.  Laser Light Scattering Study of the Phase Transition of Poly(N-isopropylacrylamide) in Water. 1. Single Chain , 1995 .

[29]  Masaru Yoshida,et al.  Synthesis of poly(N-isopropylacrylamide) hydrogels by radiation polymerization and crosslinking , 1993 .

[30]  G. Bernstein,et al.  Swelling and surface forces-induced instabilities in nanoscopic polymeric structures , 1992 .

[31]  Elsa Reichmanis,et al.  Polymer Materials for Microlithography , 1987 .

[32]  Toyoichi Tanaka,et al.  Volume‐phase transitions of ionized N‐isopropylacrylamide gels , 1987 .

[33]  Toyoichi Tanaka,et al.  Volume phase transition in a non‐ionic gel , 1984 .

[34]  G. W. Kammlott,et al.  Three dimensional behavior of negative electron resists , 1977 .

[35]  W. MacKnight.  Macromolecules. , 1976, Science.

[36]  M. Heskins,et al.  Solution Properties of Poly(N-isopropylacrylamide) , 1968 .

[37]  John Crank,et al.  Diffusion in polymers , 1968 .