nontransferring dry adhesive with hierarchical polymer nanohairs

We present a simple yet robust method for fabricating angled, hierarchically patterned high-aspect-ratio polymer nanohairs to generate directionally sensitive dry adhesives. The slanted polymeric nanostructures were molded from an etched polySi substrate containing slanted nanoholes. An angled etchi...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2009-04, Vol.106 (14), p.5639-5644
Main Authors: Jeong, Hoon Eui, Lee, Jin-Kwan, Kim, Hong Nam, Moon, Sang Heup, Suh, Kahp Y
Format: Article
Language:English
Subjects:
Adhesion
Adhesives
Biological Sciences
Biopolymers
Cell adhesion & migration
Etching
Glass
Hair
Material films
Molding
Nanoscience
Nanostructures
Optimization
Physical Sciences
Polymers
Resins
Silica
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a simple yet robust method for fabricating angled, hierarchically patterned high-aspect-ratio polymer nanohairs to generate directionally sensitive dry adhesives. The slanted polymeric nanostructures were molded from an etched polySi substrate containing slanted nanoholes. An angled etching technique was developed to fabricate slanted nanoholes with flat tips by inserting an etch-stop layer of silicon dioxide. This unique etching method was equipped with a Faraday cage system to control the ion-incident angles in the conventional plasma etching system. The polymeric nanohairs were fabricated with tailored leaning angles, sizes, tip shapes, and hierarchical structures. As a result of controlled leaning angle and bulged flat top of the nanohairs, the replicated, slanted nanohairs showed excellent directional adhesion, exhibiting strong shear attachment ([almost equal to]26 N/cm² in maximum) in the angled direction and easy detachment ([almost equal to]2.2 N/cm²) in the opposite direction, with a hysteresis value of [almost equal to]10. In addition to single scale nanohairs, monolithic, micro-nanoscale combined hierarchical hairs were also fabricated by using a 2-step UV-assisted molding technique. These hierarchical nanoscale patterns maintained their adhesive force even on a rough surface (roughness
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.0900323106