In the ultraviolet nanoimprint lithography (UV-NIL) process, the surface interaction between the mold and the resist is essential along with molecularly clean separation of the mold from the surface of the cured resist for repeated use of the mold. In our present study, various mold-resin combinations have been examined by a tensile strength method to determine the adhesion force between a mold with a relief pattern and a photocurable resin. The adhesion force of polymer molds of the fluorine-containing polymers perfluoropolyether dimethacrylate (PFPE) and polydimethylsiloxane (PDMS) were compared to those of hard molds such as Si and quartz against several commercial UV-NIL resins. Eventually, PFPE with higher molecular weight-AMONIL-was found to be an excellent UV-NIL mold-resin combination with the lowest adhesion force per unit area (20 kPa). In particular, the 36-fold repeated imprinting with a high molecular weight PFPE mold showed only a slight increase of adhesion force by 36 kPa with molecularly clean release from the AMONIL resin, whereas a surface-modified PDMS mold revealed highly increased adhesion from an initial 20 kPa to 120 kPa after repeated use.
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http://dx.doi.org/10.1088/0957-4484/20/5/055704 | DOI Listing |
Mechanical forces are critical for virtually all fundamental biological processes, yet quantification of mechanical forces at the molecular scale remains challenging. Here, we present a new strategy using calibrated coiled-coils as genetically encoded, compact, tunable, and modular mechano-sensors to substantially simplify force measurement , via diverse readouts (luminescence, fluorescence and analytical biochemistry) and instrumentation readily available in biology labs. We demonstrate the broad applicability and ease-of-use of these coiled-coil mechano-sensors by measuring forces during cytokinesis (formin Cdc12) and endocytosis (epsin Ent1) in yeast, force distributions in nematode axons (β-spectrin UNC-70), and forces transmitted to the nucleus (mini-nesprin-2G) and within focal adhesions (vinculin) in mammalian cells.
View Article and Find Full Text PDFBiomater Sci
January 2025
Department of Nanobiomedical Science & BK21 FOUR micropatterned shape-memory NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, Republic of Korea.
A scaffold design for tendon regeneration has been proposed, which mimics the microstructural features of tendons and provides appropriate mechanical properties. We synthesized a temperature-triggered shape-memory polymer (SMP) using the ring-opening polymerization of polycaprolactone (PCL) with polyethylene glycol (PEG) as a macroinitiator. We fabricated a micropatterned patch using SMP capillary force lithography, which mimicked a native tendon, for providing physical cues and guiding effects.
View Article and Find Full Text PDFSmall Methods
January 2025
School of Chemistry and Materials, Department of Chemistry, Laboratory of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, P. R. China.
The unique adhesion capabilities of soft-bodied creatures such as leeches and octopuses have provided considerable inspiration for the development of artificial adhesive materials. However, previous studies have either focused on the design of sucker structures or concentrated on the synthesis of adhesive materials, with the combination of these two aspects not yet having been deeply investigated. In this study, inspired from leech's unique adsorption ability, a biomimetic approach is proposed that combined artificial sucker and mucus, to achieve remarkable adhesion stability on rough surfaces using 5 cm diameter silicone suction cups.
View Article and Find Full Text PDFNanomicro Lett
January 2025
Fujian Provincial Key Laboratory of Fire Retardant Materials, College of Materials, Xiamen University, Xiamen, 361000, People's Republic of China.
In recent decades, annual urban fire incidents, including those involving ancient wooden buildings burned, transportation, and solar panels, have increased, leading to significant loss of human life and property. Addressing this issue without altering the surface morphology or interfering with optical behavior of flammable materials poses a substantial challenge. Herein, we present a transparent, low thickness, ceramifiable nanosystem coating composed of a highly adhesive base (poly(SSS-co-HEMA)), nanoscale layered double hydroxide sheets as ceramic precursors, and supramolecular melamine di-borate as an accelerator.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Chemistry and Chemical Technology, Manash Kozybayev North Kazakhstan University, Petropavlovsk 150000, Kazakhstan.
The aim of the work was to study the effect of additive concentration on changes in the adhesive and cohesive strength of bitumen. To evaluate the effectiveness of modifiers in the composition of binary and triple bitumen systems in relation to mineral fillers of two grades, the method of determination of the adhesive efficiency and thermodynamic calculations of adhesion and cohesion work were used. The following compounds were used as additives: synthesized from the oil refining waste and (waste sealing liquid).
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