scholarly journals Bioinspired Underwater Adhesion to Rough Substrates by Cavity Collapse of Cupped Microstructures

2021 ◽  
pp. 2101787
Author(s):  
Yue Wang ◽  
René Hensel
Keyword(s):  
Underwater Adhesion ◽  
Cavity Collapse

Conditions of inertial-viscous transition and related jetting in large cavity collapse

2020 ◽  
Vol 5 (12) ◽  
Author(s):  
D. Krishna Raja ◽  
E. J. Hopfinger ◽  
S. P. Das
Keyword(s):  
Large Cavity ◽  
Cavity Collapse

Attractive forces slow contact formation between deformable bodies underwater

2021 ◽  
Vol 118 (41) ◽  
pp. e2104975118
Author(s):  
Mengyue Sun ◽  
Nityanshu Kumar ◽  
Ali Dhinojwala ◽  
Hunter King
Keyword(s):  
Three Dimensional ◽  
Adhesive Contact ◽  
Final State ◽  
Underwater Adhesion ◽  
Frustrated Total Internal Reflection ◽  
Solid Deformation ◽  
Hydrophilic Surfaces ◽  
Deformable Bodies ◽  
Adhesive Interactions

Thermodynamics tells us to expect underwater contact between two hydrophobic surfaces to result in stronger adhesion compared to two hydrophilic surfaces. However, the presence of water changes not only energetics but also the dynamic process of reaching a final state, which couples solid deformation and liquid evacuation. These dynamics can create challenges for achieving strong underwater adhesion/friction, which affects diverse fields including soft robotics, biolocomotion, and tire traction. Closer investigation, requiring sufficiently precise resolution of film evacuation while simultaneously controlling surface wettability, has been lacking. We perform high-resolution in situ frustrated total internal reflection imaging to track underwater contact evolution between soft-elastic hemispheres of varying stiffness and smooth–hard surfaces of varying wettability. Surprisingly, we find the exponential rate of water evacuation from hydrophobic–hydrophobic (adhesive) contact is three orders of magnitude lower than that from hydrophobic–hydrophilic (nonadhesive) contact. The trend of decreasing rate with decreasing wettability of glass sharply changes about a point where thermodynamic adhesion crosses zero, suggesting a transition in mode of evacuation, which is illuminated by three-dimensional spatiotemporal height maps. Adhesive contact is characterized by the early localization of sealed puddles, whereas nonadhesive contact remains smooth, with film-wise evacuation from one central puddle. Measurements with a human thumb and alternatively hydrophobic/hydrophilic glass surface demonstrate practical consequences of the same dynamics: adhesive interactions cause instability in valleys and lead to a state of more trapped water and less intimate solid–solid contact. These findings offer interpretation of patterned texture seen in underwater biolocomotive adaptations as well as insight toward technological implementation.

scholarly journals Preservation of minimally processed 'aurora-1' peaches using additives

2011 ◽  
Vol 33 (4) ◽  
pp. 1229-1239 ◽  
Author(s):  
Ramilo Nogueira Martins ◽  
Ben-Hur Mattiuz ◽  
Leandra Oliveira Santos ◽  
Cristiane Maria Ascari Morgado ◽  
Claudia Fabrino Machado Mattiuz
Keyword(s):  
Ascorbic Acid ◽  
Shelf Life ◽  
Ascorbic Acid Content ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Enzymatic Browning ◽  
Soluble Carbohydrates ◽  
Minimally Processed ◽  
Minimal Processing ◽  
Cavity Collapse

'Aurora-1' peaches establishes an interesting alternative as a minimally processed product, due to its characteristics like flavor, color, smell, and also because of its handling resistance. However, it has a short shelf life after a fresh-cut due to enzymatic browning and stone cavity collapse. The main purpose of this research was to test the additive with antioxidant effect to prevent browning in minimally processed 'Aurora-1' peaches. The minimal processing consists of washing, sanitizing, peelings and fruit stone extraction. After that, longitudinal cuts were made to obtain eight segments per fruit. The slices were immersed into the following treatment solutions: control (immersion in 2% ascorbic acid); 2% ascorbic acid + 2% calcium chloride; 1% sodium isoascorbate; 1% citric acid; 1% L-cysteine hydrochloride. The products were placed into rigid polystyrene trays branded MEIWA M-54, covered with 14 µm PVC film (OmnifilmTM) and kept in cold storage at 3ºC ± 2ºC and 65% RH for twelve days, and evaluated each three days. Appraised variables were appearance, soluble solids, titratable acidity, soluble carbohydrates and reducing sugars, total and soluble pectin, ascorbic acid, and peroxidase and polyphenol oxidase enzyme activity. L-cysteine gave to the minimally processed products a shelf life of twelve days, limmited by off-flavor. The treatment with ascorbic acid was efficient to maintainthe ascorbic acid content, with a shelf-life of nine days, limited by enzymatic browning.

scholarly journals Towards cavity-collapse hazard maps with Zeb-Revo handheld laser scanner point clouds

2017 ◽  
Vol 32 (160) ◽  
pp. 354-376 ◽  
Author(s):  
Thomas J. B. Dewez ◽  
Silvain Yart ◽  
Ysoline Thuon ◽  
Pierre Pannet ◽  
Emmanuelle Plat
Keyword(s):  
Laser Scanner ◽  
Point Clouds ◽  
Hazard Maps ◽  
Cavity Collapse

A Biosynthetic Hybrid Spidroin-Amyloid-Mussel Foot Protein for Underwater Adhesion on Diverse Surfaces

2021 ◽  
Author(s):  
Eugene Kim ◽  
Juya Jeon ◽  
Yaguang Zhu ◽  
Ethan D. Hoppe ◽  
Young-Shin Jun ◽  
...  
Keyword(s):  
Underwater Adhesion ◽  
Mussel Foot Protein

Strong underwater adhesion of injectable hydrogels triggered by diffusion of small molecules

2021 ◽  
Author(s):  
Xing Su ◽  
Wenyue Xie ◽  
Pudi Wang ◽  
Zhuoling Tian ◽  
Hao Wang ◽  
...  
Keyword(s):  
Small Molecules ◽  
Tea Polyphenols ◽  
Injectable Hydrogels ◽  
Injectable Hydrogel ◽  
Underwater Adhesion ◽  
Physically Crosslinked

It is challenging for injectable hydrogels to achieve high underwater adhesiveness. Based on this concern, we report a fully physically crosslinked injectable hydrogel composed of gelatin, tea polyphenols and urea,...

Sign in / Sign up

Export Citation Format

Share Document