Search results for "Printing"
showing 10 items of 532 documents
DNA-Assisted Molecular Lithography
2018
During the past decade, DNA origami has become a popular method to build custom two- (2D) and three-dimensional (3D) DNA nanostructures. These programmable structures could further serve as templates for accurate nanoscale patterning, and therefore they could find uses in various biotechnological applications. However, to transfer the spatial information of DNA origami to metal nanostructures has been limited to either direct nanoparticle-based patterning or chemical growth of metallic seed particles that are attached to the DNA objects. Here, we present an alternative way by combining DNA origami with conventional lithography techniques. With this DNA-assisted lithography (DALI) method, we…
"Smart" defects in colloidal photonic crystals
2005
AbstractWe present a bottom-up approach for the construction of "Smart" active defects in colloidal photonic crystals (CPCs). These structures incorporate polyelectrolyte multilayer (PEM) planar defects embedded in silica CPCs through a combination of evaporation induced self-assembly and microcontact transfer printing. We show how the enormous chemical diversity inherent to PEMs can be harnessed to create chemically active defect structures responsive to solvent vapor pressures, light, temperature as well as redox cycling. A sharp transmission state within the photonic stopband, induced by the PEM defect, can be precisely, reproducibly and in some cases reversibly tuned by these external s…
One-Component DNA Mechanoprobes for Facile Mechanosensing in Photopolymerized Hydrogels and Elastomers.
2021
DNA mechanosensors offer unique properties for mechano-adaptive and self-reporting materials, such as programmable bond strength and geometrical strain response, tunable fluorescent strain sensing, interfacing to biological systems, and the ability to store mechanical information. However, the facile incorporation of advanced DNA motifs into polymer networks and achieving robustness in application settings remain difficult. Herein, we introduce one-component DNA mechanoprobes that can be easily polymerized into polymer hydrogels and even elastomers to allow strain-induced fluorescence sensing. The all-in-one mechanoprobe contains a DNA hairpin for programmable force sensing, an internal flu…
Poly(N-isopropylacrylamide) and Copolymers: A Review on Recent Progresses in Biomedical Applications.
2017
The innate ability of poly(N-isopropylacrylamide) (PNIPAAm) thermo-responsive hydrogel to copolymerize and to graft synthetic polymers and biomolecules, in conjunction with the highly controlled methods of radical polymerization which are now available, have expedited the widespread number of papers published in the last decade—especially in the biomedical field. Therefore, PNIPAAm-based hydrogels are extensively investigated for applications on the controlled delivery of active molecules, in self-healing materials, tissue engineering, regenerative medicine, or in the smart encapsulation of cells. The most promising polymers for biodegradability enhancement of PNIPAAm hydrogels are probably…
Smart polymeric coatings for damage visualization in substrate materials
2012
For damage indication needs in polymer composites, three smart acrylic coatings based on microencapsulated crystal violet lactone leuco dye with embedded developer silica gel and methyl 4-hydroxybenzoate were elaborated. Damage visualization ability upon duralumin substrates was tested. Indentation tests were conducted in the interval of 0.0005–0.55 J of mechanical work. Digital image analysis was used for evaluation of the visual response in the form of “bruise” spots. The measure of response intensity was relative excess of blue color above achromatic gray in the scanned images of the “bruise” spots. This technique allowed detecting influence of the coating formulations onto the substrat…
Biosilica electrically-insulating layers by soft lithography-assisted biomineralisation with recombinant silicatein.
2011
Effects of Different Test Setups on the Experimental Tensile Behaviour of Basalt Fibre Bidirectional Grids for FRCM Composites
2020
Fibre-reinforced cementitious matrix (FRCM) composites have been effectively used during the last ten years for the strengthening of existing concrete and masonry structures. These composite materials are made of medium- and high-strength fibre meshes embedded in inorganic matrices. Synthetic fibres are the ones that are currently the most used
3D Bioprinting for Vascularized Tissue-Engineered Bone Fabrication
2020
Vascularization in bone tissues is essential for the distribution of nutrients and oxygen, as well as the removal of waste products. Fabrication of tissue-engineered bone constructs with functional vascular networks has great potential for biomimicking nature bone tissue in vitro and enhancing bone regeneration in vivo. Over the past decades, many approaches have been applied to fabricate biomimetic vascularized tissue-engineered bone constructs. However, traditional tissue-engineered methods based on seeding cells into scaffolds are unable to control the spatial architecture and the encapsulated cell distribution precisely, which posed a significant challenge in constructing complex vascul…
Experimental investigation of effect of printing direction and surface roughness on the mechanical properties of AlSi10Mg-alloy produced by selective…
2021
The additive manufacturing has initially gained popularity for production of non-loadbearing parts and components or in the fields where the material strength and ductility are less important such as modelling and rapid prototyping. But as the technology develops, availability of metal additive manufacturing naturally dictates the desire to use the produced components in load-bearing parts. This requires not-only a thorough documentation on the mechanical properties but also additional and independent research to learn the expected level of variation of the mechanical properties and what factors affect them. The presented paper investigates strength, ductility, hardness, and microstructure …