Adhesion of Flat and Structured PDMS Samples to Spherical and Flat Probes: A Comparative Study

Kroner, Elmar; Paretkar, Dadhichi; McMeeking, Robert M.; Arzt, Eduard

doi:10.1080/00218464.2011.575317

Cited by 43 publications

(47 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results for the rough substrates GS1 and GS3 and the smooth control are shown as double-logarithmic plots in Figure 3 A. Adhesion is seen to decrease strongly with increasing roughness, which is in agreement with earlier studies with unpatterned elastomeric specimens. [33][34][35] In addition, the pull-off stress for the smooth substrate was found to be preload independent in line with our earlier studies, [ 36 ] whereas a strong infl uence of preload was observed for the rough substrates. This fi nding is signifi cant and will be discussed in more detail in the next section.…”

Section: Resultssupporting

confidence: 86%

Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces

Barreau

Hensel

Guimard

et al. 2016

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

Biologically inspired, fi brillar dry adhesives continue to attract much attention as they are instrumental for emerging applications and technologies. To date, the adhesion of micropatterned gecko-inspired surfaces has predominantly been tested on stiff, smooth substrates. However, all natural and almost all artifi cial surfaces have roughnesses on one or more different length scales. In the present approach, micropillar-patterned PDMS surfaces with superior adhesion to glass substrates with different roughnesses are designed and analyzed. The results reveal for the fi rst time adhesive and nonadhesive states depending on the micropillar geometry relative to the surface roughness profi le. The data obtained further demonstrate that, in the adhesive regime, fi brillar gecko-inspired adhesive structures can be used with advantage on rough surfaces; this fi nding may open up new applications in the fi elds of robotics, biomedicine, and space exploration.

show abstract

Section: Resultssupporting

confidence: 86%

Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces

Barreau

Hensel

Guimard

et al. 2016

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…Different sample alignments for type 2 adhesives with round edges failed to show a drastic adhesion response as a function of preload stress (see the electronic supplementary material, figure S6). The maxima in pull-off strength were lower in the 'misaligned' state, consistent with previous results [31].…”

Section: Point 4: Sample Alignmentsupporting

confidence: 92%

Preload-responsive adhesion: effects of aspect ratio, tip shape and alignment

Paretkar

Kamperman

Martina

et al. 2013

J. R. Soc. Interface.

Self Cite

View full text Add to dashboard Cite

We tested the adhesive response of polymer surfaces structured with arrays of cylindrical fibrils having diameters of 10 -20 mm and aspect ratios 1-2.4. Fibrils had two different tip shapes of end-flaps and round edges. A preloadinduced mechanical buckling instability of the fibrils was used to switch between the states of adhesion and non-adhesion. Non-adhesion in fibrils with round edges was reached at preloads that caused fibril buckling, whereas fibrils with end-flaps showed adhesion loss only at very high preloads. The round edge acted as a circumferential flaw prohibiting smooth tip contact recovery leading to an adhesion loss. In situ observations showed that, after reversal of buckling, the end-flaps unfold and re-form contact under prevailing compressive stress, retaining adhesion in spite of buckling. At very high preloads, however, end-flaps are unable to re-form contact resulting in adhesion loss. Additionally, the end-flaps showed varying contact adaptability as a function of the fibril -probe alignment, which further affects the preload for adhesion loss. The combined influence of preload, tip shape and alignment on adhesion can be used to switch adhesion in bioinspired fibrillar arrays.

show abstract

“…[20,21] In practice, however, these stresses are typically in the range of several hundreds of kilopascals or below. [22][23][24][25] The discrepancy is most likely caused by nonideal contact and detachment conditions: possible causes are, besides surface roughness, unequal load sharing, [26] or flaws and local stress concentrations. [27][28][29][30] Therefore, tailoring the stress distribution along the fibril-substrate interface by reducing such stress concentrations is a major objective in fabricating synthetic fibrillar dry adhesives with high pull-off stresses.…”

Section: Introductionmentioning

confidence: 99%

Funnel‐Shaped Microstructures for Strong Reversible Adhesion

Fischer

Groß

Abad

et al. 2017

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

The potential of a new design of adhesive microstructures in the micrometer range for enhanced dry adhesion is investigated. Using a two‐photon lithography system, complex 3D master structures of funnel‐shaped microstructures are fabricated for replication into poly(ethylene glycol) dimethacrylate polymer. The diameter, the flap thickness, and the opening angle of the structures are varied systematically. The adhesion of single structures is characterized using a triboindenter system equipped with a flat diamond punch. The pull‐off stresses obtained reaches values up to 5.6 MPa, which is higher than any values reported in literature for artificial dry adhesives. Experimental and numerical results suggest a characteristic attachment mechanism that leads to intimate contact formation from the edges toward the center of the structures. van der Waals interactions most likely dominate the adhesion, while contributions by suction or capillarity play only a minor role. Funnel‐shaped microstructures are a promising concept for strong and reversible adhesives, applicable in novel pick and place handling systems or wall‐walking robots.

show abstract

Adhesion of Flat and Structured PDMS Samples to Spherical and Flat Probes: A Comparative Study

Cited by 43 publications

References 35 publications

Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces

Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces

Preload-responsive adhesion: effects of aspect ratio, tip shape and alignment

Funnel‐Shaped Microstructures for Strong Reversible Adhesion

Contact Info

Product

Resources

About