The surface functionalization of TiO2-based materials with alkylsilanes is attractive in several cutting-edge applications, such as photovoltaics, sensors, and nanocarriers for the controlled release of bioactive molecules. (3-Aminopropyl)triethoxysilane (APTES) is able to self-assemble to form monolayers on TiO2 surfaces, but its adsorption geometry and solar-induced photodegradation pathways are not well understood. We here employ advanced experimental (XPS, NEXAFS, AFM, HR-TEM, and FT-IR) and theoretical (plane-wave DFT) tools to investigate the preferential interaction mode of APTES on anatase TiO2. We demonstrate that monomeric APTES chemisorption should proceed through covalent Si–O–Ti bonds. Although dimerization of the silane through Si–O–Si bonds is possible, further polymerization on the surface is scarcely probable. Terminal amino groups are expected to be partially involved in strong charge-assisted hydrogen bonds with surface hydroxyl groups of TiO2, resulting in a reduced propensity to react...

https://researchbank.swinburne.edu.au/file/2ad33ddd-b905-4339-9db1-18763544ddda/1/2017_meroni_a close look at.pdf

A Close Look at the Structure of the TiO2-APTES Interface in Hybrid Nanomaterials and Its Degradation Pathway: An Experimental and Theoretical Study

With the increasing application of orthopedic scaffolds, a dramatically increasing number of requirements for scaffolds are precise The porous structure has been a fundamental design in the bone tissue engineering or orthopedic clinics because of its low Young's modulus, high compressive strength, and abundant cell accommodation space The porous structure manufactured by additive manufacturing (AM) technology has controllable pore size, pore shape, and porosity The single unit can be designed and arrayed with AM, which brings controllable pore characteristics and mechanical properties This paper presents the current status of porous designs in AM technology The porous structures are stated from the cellular structure and the whole structure In the aspect of the cellular structure, non-parametric design and parametric design are discussed here according to whether the algorithm generates the structure or not The non-parametric design comprises the diamond, the body-centered cubic, and the polyhedral structure, etc The Voronoi, the Triply Periodic Minimal Surface, and other parametric designs are mainly discussed in parametric design In the discussion of cellular structures, we emphasize the design, and the resulting biomechanical and biological effects caused by designs In the aspect of the whole structure, the recent experimental researches are reviewed on uniform design, layered gradient design, and layered gradient design based on topological optimization, etc These parts are summarized because of the development of technology and the demand for mechanics or bone growth Finally, the challenges faced by the porous designs and prospects of porous structure in orthopedics are proposed in this paper

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Porous Scaffold Design for Additive Manufacturing in Orthopedics: A Review.

With the increase of communication frequency, terahertz (THz) communication technology has been an important research field; particularly the terahertz modulator is becoming one of the core devices in THz communication system. The modulation performance of a THz communication system depends on the characterization of THz modulator. THz modulators based on different principles and materials have been studied and developed. However, they are still on the way to practical application due to low modulation speed, narrow bandwidth, and insufficient modulation depth. Therefore, we review the research progress of THz modulator in recent years and evaluate devices critically and comprehensively. We focus on the working principles such as electric, optical, optoelectrical, thermal, magnetic, programmable metamaterials and nonlinear modulation methods for THz wave with semiconductors, metamaterials, and 2D materials (such as graphene, molybdenum disulfide, and tungsten disulfide). Furthermore, we propose a guiding rule to select appropriate materials and modulation methods for specific applications in THz communication.

/pdf/modulators-for-terahertz-communication-the-current-state-of-4fm7s07jrl.pdf

Modulators for Terahertz Communication: The Current State of the Art.

Hydrographic printing is a well-known technique in industry for transferring color inks on a thin film to the surface of a manufactured 3D object. It enables high-quality coloring of object surfaces and works with a wide range of materials, but suffers from the inability to accurately register color texture to complex surface geometries. Thus, it is hardly usable by ordinary users with customized shapes and textures. We present computational hydrographic printing, a new method that inherits the versatility of traditional hydrographic printing, while also enabling precise alignment of surface textures to possibly complex 3D surfaces. In particular, we propose the first computational model for simulating hydrographic printing process. This simulation enables us to compute a color image to feed into our hydrographic system for precise texture registration. We then build a physical hydrographic system upon off-the-shelf hardware, integrating virtual simulation, object calibration and controlled immersion. To overcome the difficulty of handling complex surfaces, we further extend our method to enable multiple immersions, each with a different object orientation, so the combined colors of individual immersions form a desired texture on the object surface. We validate the accuracy of our computational model through physical experiments, and demonstrate the efficacy and robustness of our system using a variety of objects with complex surface textures.

Computational hydrographic printing

We propose FlexMaps, a novel framework for fabricating smooth shapes out of flat, flexible panels with tailored mechanical properties. We start by mapping the 3D surface onto a 2D domain as in traditional UV mapping to design a set of deformable flat panels called FlexMaps. For these panels, we design and obtain specific mechanical properties such that, once they are assembled, the static equilibrium configuration matches the desired 3D shape. FlexMaps can be fabricated from an almost rigid material, such as wood or plastic, and are made flexible in a controlled way by using computationally designed spiraling microstructures.

Randy Deutsch

Papers

Design and Fabrication