TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Tinnemann, Verena
A1  - Hernández, Luissé
A1  - Fischer, Sarah
A1  - Arzt, Eduard
A1  - Bennewitz, Roland
A1  - Hensel, René
T1  - In Situ Observation Reveals Local Detachment Mechanisms and Suction Effects in Micropatterned Adhesives
JF  - Advanced Functional Materials
N2  - Fibrillar adhesion pads of insects and geckoes have inspired the design of high-performance adhesives enabling a new generation of handling devices. Despite much progress over the last decade, the current understanding of these adhesives is limited to single contact pillars and the behavior of whole arrays is largely unexplored. In the study reported here, a novel approach is taken to gain insight into the detachment mechanisms of whole micropatterned arrays. Individual contacts are imaged by frustrated total internal reflection, allowing in situ observation of contact formation and separation during adhesion tests. The detachment of arrays is found to be governed by the distributed adhesion strength of individual pillars, but no collaborative effect mediated by elastic interactions can be detected. At the maximal force, about 30% of the mushroom structures are already detached. The adhesive forces decrease with reduced air pressure by 20% for the smooth and by 6% for the rough specimen. These contributions are attributed to a suction effect, whose strength depends critically on interfacial defects controlling the sealing quality of the contact. This dominates the detachment process and the resulting adhesion strength.
KW  - adhesion
KW  - bioinspiration
KW  - elastic coupling
KW  - in-situ observation
KW  - micropatterning
Y1  - 2019
UN  - https://nbn-resolving.org/urn:nbn:de:bsz:291:415-1549
U6  - https://doi.org/10.1002/adfm.201807713
DO  - https://doi.org/10.1002/adfm.201807713
VL  - 29
SP  - 1807713
ER  -