Video-based action recognition is becoming a vital tool in clinical research and neuroscientific study for disorder detection and prediction. However, action recognition currently used in non-human primate (NHP) research relies heavily on intense manual labor and lacks standardized assessment. In this work, we established two standard benchmark datasets of NHPs in the laboratory: MonkeyinLab (MiL), which includes 13 categories of actions and postures, and MiL2D, which includes sequences of two-dimensional (2D) skeleton features. Furthermore, based on recent methodological advances in deep learning and skeleton visualization, we introduced the MonkeyMonitorKit (MonKit) toolbox for automatic action recognition, posture estimation, and identification of fine motor activity in monkeys. Using the datasets and MonKit, we evaluated the daily behaviors of wild-type cynomolgus monkeys within their home cages and experimental environments and compared these observations with the behaviors exhibited by cynomolgus monkeys possessing mutations in the MECP2 gene as a disease model of Rett syndrome (RTT). MonKit was used to assess motor function, stereotyped behaviors, and depressive phenotypes, with the outcomes compared with human manual detection. MonKit established consistent criteria for identifying behavior in NHPs with high accuracy and efficiency, thus providing a novel and comprehensive tool for assessing phenotypic behavior in monkeys.
Directed Self-Assembly (DSA) of cylindrical block copolymer with graphoepitaxy strategy offering significant potential for contact hole multiplication in semiconductor manufacturing at technology nodes below 7 nm (sub-7 nm). This technique allows precise control over the number of DSA-generated holes and their critical dimensions (CD) by manipulating the guiding template geometry and size. The results indicate that DSA quadruple-hole multiplication patterns aligned top-bottom and left-right, with a long-axis spacing of 55-65 nm and a short-axis spacing of 30-40 nm could be achieved through precisely designing template holes with long-axis dimension and short-axis dimension. The formed DSA pattern was successfully transferred to the underlying hard mask layer, creating a large-area quadruple-hole array with a CD of approximately 17 nm. A comprehensive investigation of guiding template size and morphology on multiplication hole patterning enhances the understanding of the self-assembly behavior in confined elliptical spaces. In conclusion, this work highlights the importance of optimizing guiding template size for contact hole multiplication in integrated circuit fabrication.
Directed self-assembly (DSA) of block copolymers (BCPs) is a leading strategy to pattern at sublithographic resolution in the technology roadmap for semiconductors and is the only known solution to fabricate nanoimprint templates for the production of bit pattern media. While great progress has been made to implement block copolymer lithography with features in the range of 10–20 nm, patterning solutions below 10 nm are still not mature. Many BCP systems self-assemble at this length scale, but challenges remain in simultaneously tuning the interfacial energy atop the film to control the orientation of BCP domains, designing materials, templates, and processes for ultra-high-density DSA, and establishing a robust pattern transfer strategy. Among the various solutions to achieve domains that are perpendicular to the substrate, solvent annealing is advantageous because it is a versatile method that can be applied to a diversity of materials. Here we report a DSA process based on chemical contrast templates and solvent annealing to fabricate 8 nm features on a 16 nm pitch. To make this possible, a number of innovations were brought in concert with a common platform: (1) assembling the BCP in the phase-separated, solvated state, (2) identifying a larger process window for solvated triblock vs diblock BCPs as a function of solvent volume fraction, (3) employing templates for sub-10-nm BCP systems accessible by lithography, and (4) integrating a robust pattern transfer strategy by vapor infiltration of organometallic precursors for selective metal oxide synthesis to prepare an inorganic hard mask.
In this work, we demonstrate a focused solar annealing (FSA) technique that is facile, eco-friendly, and energy-efficient for fast self-assembly of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) films. The FSA principle is employing a common biconvex lens to converge the normal solar radiation into a high-temperature spot, which is directly used to drive the microphase separation of PS-b-PMMA films. As a result, PS-b-PMMA self-assembles into highly ordered nanostructures with a vertical orientation at seconds timescales. Additionally, the FSA technique can be employed for grafting neutral polymer brushes onto the silicon substrate. Furthermore, the compatibility of the FSA with directed self-assembly (DSA) of BCP by graphoepitaxy is demonstrated in the patterning of contact holes. The results of contact hole shrinking show that contact hole prepatterns of ~60.4 nm could be uniformly shrunk to ~20.5 nm DSA hole patterns. For contact hole multiplication, doublet DSA holes were formed on elliptical templates, showing an average DSA hole size of ~21.3 nm. Most importantly, due to the direct use of solar energy, the FSA technique provides many significant advantages such as simplicity, environmental friendliness, solvent-free, low cost, and net-zero carbon emissions, and will open up a new direction for BCP lithography that is sustainable, pollution-free, and carbon-neutral.
We study the surface plasmon enhanced fluorescence where an emitter is embedded in a metal nanoshell. Both simulation and experimental results are presented.
Transformation of 2D Au nanoparticle (NP) arrays into large scale, ordered, and oriented nanorod/nanowire arrays supported on a transferrable polymer film has been accomplished. E-beam irradiation followed by room temperature aging of a suspended Au NP/polymethylmethacrylate (PMMA) polymer close packed monolayer results in one-dimensional nanoparticle aggregation, reorientation, and sintering into a high density array of oriented Au nanowires with coherent single-crystal-like interfaces. Molecular dynamics simulations of alkane-thiol capped Au NPs, interacting through the Vincent potential and undergoing 2D Poisson compression, account semiquantitatively for the qualitative features of the transformation. This fabrication approach should be extendable to directing 1D aggregation of highly anisotropic nanostructures in arbitrary NP systems.
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