Easy soft imprint nanolithography (ESINL) is employed in the patterning of multiple olymer brushes. This new approach to soft lithography is found to be uniquely effective at patterning brushes both prior to and subsequent to grafting of the polymer chains. Silicon substrates are grafted with polystyrene, polymethylmethacrylate, and polyhydroxyethylmethacrylate using surface-initiated atom transfer radical polymerization assisted by activators generated by electron transfer (ARGET-ATRP) and characterized by contact angle measurements, infrared spectroscopy, and ellipsometry. Line grating features of 3 cm × 3 cm with critical dimensions in the range of 410-480 nm are imprinted directly over grafted brush layers or over assembled monolayers of initiator molecules and transferred to the active layer by reactive ion etching. In all cases the grating pattern is accurately reproduced in the brush layer as confirmed by atomic force microscopy, demonstrating the capability of the technique to generate large-area nanoscale patterns on a range of surface types and functionalities.
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http://dx.doi.org/10.1002/smll.201100895 | DOI Listing |
Biomater Transl
September 2024
Biomedical Engineering Program, Westlake University, Hangzhou, Zhejiang Province, China.
Bone, cartilage, and soft tissue regeneration is a complex process involving many cellular activities across various cell types. Autografts remain the "gold standard" for the regeneration of these tissues. However, the use of autografts is associated with many disadvantages, including donor scarcity, the requirement of multiple surgeries, and the risk of infection.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State Key Laboratory of Luminescent Materials and Devices &, South China Advanced Institute for Soft Matter Science and Technology, Guangdong Basic Research Center of Excellence for Energy &, Information Polymer Materials, South China University of Technology, 510640, Guangzhou, P. R. China.
Nanoimprint lithography (NIL) has been broadly applied in the fabrication of nano-patterned polymer films for cost-efficiency and high through-put; however, the intrinsic tradeoff between mechanical strength and residual stress of polymer films significantly limits the NIL resolution while the harsh processing conditions limit its versatile applications to different substrates. Herein, 1 nm metal oxide cluster, phosphotungstic acid (PTA), is used to complex with polyvinyl alcohol (PVA) for high-resolution NIL that can be operated at large-scale and mild conditions. The ultra-small size of PTA enables dense supramolecular interaction with PVA for the diminished crystallinity and accelerated chain dynamics that help relax the residual stress during film casting.
View Article and Find Full Text PDFNanomaterials (Basel)
November 2024
Nanotechnology Group, USAL-Nanolab, Departamento de Física Fundamental, Universidad de Salamanca (USAL), E-37008 Salamanca, Spain.
The ability to manufacture complex 3D structures with nanometer-scale resolution, such as Fresnel Zone Plates (FZPs), is crucial to achieve state-of-the-art control in X-ray sources for use in a diverse range of cutting-edge applications. This study demonstrates a novel approach combining Electron Beam Lithography (EBL) and cryoetching to produce silicon-based FZP prototypes as a test bench to assess the strong points and limitations of this fabrication method. Through this method, we obtained FZPs with 100 zones, a diameter of 20 µm, and an outermost zone width of 50 nm, resulting in a high aspect ratio that is suitable for use across a range of photon energies.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Sericulture, Textile and Biomass Sciences, State Key Laboratory of Resource Insects, Southwest University, Chongqing 400715, China. Electronic address:
Scar formation and chronic refractory wounds pose a significant threat to public health, with abnormal immune regulation as a key characteristic. However, topography, a crucial factor influencing immune responses, has not been adequately considered in the design of wound dressings. In this study, we constructed a hierarchical structure on silk fibroin (SF) films by combining soft lithography and femtosecond laser ablation, without altering the intrinsic properties of SF.
View Article and Find Full Text PDFLab Chip
December 2024
Department of Smart Health Science and Technology, Kangwon National University, Chuncheon, Republic of Korea.
Despite considerable animal sacrifices and investments, drug development often falters in clinical trials due to species differences. To address this issue, specific models, such as organ-on-a-chip technology using human cells in microfluidic devices, are recognized as promising alternatives. Among the various organs, the human small intestine plays a pivotal role in drug development, particularly in the assessment of digestion and nutrient absorption.
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