mz7b00829_si_001.pdf (1.96 MB)
Flexible and Shape-Reconfigurable Hydrogel Interlocking Adhesives for High Adhesion in Wet Environments Based on Anisotropic Swelling of Hydrogel Microstructures
journal contribution
posted on 2017-11-14, 18:50 authored by Hyun-Ha Park, Minho Seong, Kahyun Sun, Hangil Ko, Sang Moon Kim, Hoon Eui JeongThis
study presents wet-responsive, shape-reconfigurable, and flexible
hydrogel adhesives that exhibit strong adhesion under wet environments
based on reversible interlocking between reconfigurable microhook
arrays. The experimental investigation on the swelling behavior and
structural characterization of the hydrogel microstructures reveal
that the microhook arrays undergo anisotropic swelling and shape transformation
upon contact with water. The adhesion between the interlocked microhook
arrays is greatly enhanced under wet conditions because of the hydration-triggered
shape reconfiguration of the hydrogel microstructures. Furthermore,
wet adhesion monotonically increases with water-exposure time. A maximum
adhesion force of 79.9 N cm–2 in the shear direction
is obtained with the hydrogel microhook array after 20 h of swelling,
which is 732.3% greater than that under dry conditions (i.e., 9.6
N cm–2). A simple theoretical model is developed
to describe the measured adhesion forces. The results are in good
agreement with the experimental data.