The Experts below are selected from a list of 930 Experts worldwide ranked by ideXlab platform

H. Jerry Qi - One of the best experts on this subject based on the ideXlab platform.

  • Direct Ink Write (DIW) 3D Printed Cellulose Nanocrystal Aerogel Structures
    Scientific Reports, 2017
    Co-Authors: Vincent Chi Fung Li, Conner K. Dunn, Zhe Zhang, Yulin Deng, H. Jerry Qi
    Abstract:

    Pure cellulose nanocrystal (CNC) aerogels with controlled 3D structures and inner pore architecture are printed using the direct ink write (DIW) technique. While traditional cellulosic aerogel processing approaches lack the ability to easily fabricate complete aerogel structures, DIW 3D Printing followed by freeze drying can overcome this shortcoming and can produce CNC aerogels with minimal structural shrinkage or damage. The resultant products have great potential in applications such as tissue scaffold templates, drug delivery, packaging, etc., due to their inherent sustainability, biocompatibility, and biodegradability. Various 3D structures are successfully printed without support material, and the print quality can be improved with increasing CNC concentration and Printing Resolution. Dual pore CNC aerogel scaffolds are also successfully printed, where the customizable 3D structure and inner pore architecture can potentially enable advance CNC scaffold designs suited for specific cell integration requirements.

  • Digital manufacture of shape changing components
    Extreme Mechanics Letters, 2015
    Co-Authors: Kai Yu, Martin L Dunn, H. Jerry Qi
    Abstract:

    In this paper, we demonstrate the feasibility of controlling the shape changing sequence of shape memory polymers created from digital manufacturing by exploiting multi-shape memory effects. We create shape memory polymer components with precise architectures by 3D Printing. After subjecting them to model-based thermomechanical programming steps, the components assume specified configurations in a precisely controlled shape changing sequence. The use of the 3D Printing technique enables the digital manufacturing route with the advantages of easy implementation, large design freedom, and high Printing Resolution of shape memory polymer components. The results in this paper provide a method for precisely controlling the shape recovery profile and enabling the manufacture of devices with complicated geometries and unprecedented multifunctional performance.

  • Controlled Sequential Shape Changing Components by 3D Printing of Shape Memory Polymer Multimaterials
    Procedia IUTAM, 2015
    Co-Authors: Kai Yu, Yiqi Mao, Alexander Ritchie, Martin L Dunn, H. Jerry Qi
    Abstract:

    In this paper, we demonstrate the feasibility of using 3D Printing technique to create functional graded shape memory polymers (SMPs) with both spontaneous and sequential shape recovery abilities. The created SMP components, with properly assigned spatial variation of the thermodynamical property distribution, react rapidly to a thermal stimulus, and return to a specified configuration in a precisely controlled shape changing sequence. The use of the 3D Printing technique enables a manufacturing routine with merits of easy implementation, large design freedom, and high Printing Resolution, which promises to advance immediate engineering applications for low-cost, rapid, and mass production.

Marc Arsicault - One of the best experts on this subject based on the ideXlab platform.

  • New Printing Robot for High-Resolution Pictures on Three-Dimensional Wide Surfaces
    IEEE Transactions on Industrial Electronics, 2011
    Co-Authors: Jean-pierre Gazeau, Saïd Zeghloul, Marc Arsicault
    Abstract:

    A novel five-axes robot for industrial large Printing applications is presented in this paper. The robot was developed in the robotics team from PRIME institute and an international patent was deposited for this invention in 2006. It concerns large-format 3-D Printing on a fixed surface, like trailer tarpaulin for example. The robot is composed of an inkjet Printing block and a device to dry the ink sprayed onto the surface. Kinematics of the mechanical device with 5 DOF was studied to position and orientate the printheads onto the surface to be printed. The structure of the robot is simple with high-speed capability and Printing Resolution. The working principle and mechanical structure are described, and the geometrical model and surface following control of the robot are also discussed. Finally, Printing results in a practical situation illustrate the efficiency of the proposed 3-D Printing robot, and an analysis of how the task is carried out is provided.

Wai Yee Yeong - One of the best experts on this subject based on the ideXlab platform.

  • Resolution and shape in bioPrinting : strategizing towards complex tissue and organ Printing
    Applied physics reviews, 2019
    Co-Authors: Wei Long Ng, Wai Yee Yeong
    Abstract:

    In 3D bioPrinting, Printing Resolution represents the deposited material in the x- and y-axes, while dimensionality defines the structural Resolution of printed constructs. Dimensionality in 3D bioPrinting can be defined as the Resolution in the z-axis. The Printing Resolution, together with dimensionality, contributes to the overall shape fidelity of the bioprinted constructs. The in-depth understanding of physical processes for different Printing technologies is imperative in controlling the print Resolution and definition. In this article, bioPrinting technologies are classified according to the physical processes that deposit or form the bioprinted construct. Due to the different fabrication processes in forming fundamental printed units (voxels), the definition of printability differs for each bioPrinting technique. Another aspect of Resolution is the spatial positioning of cells within each fundamental building unit. The proximity of cells in the bioprinted construct affects the physiological outcomes. The second aspect of 3D bioPrinting technologies is the ability to control shape fidelity. Different strategies have been used to improve the construction of a 3D engineered tissue or organ. Lastly, moving toward complex tissue Printing involves adding functionalities to the bioprinted construct. Data processing, material formulations, and integration of different fabrication technologies are key areas in bioPrinting that can recapture the different hierarchical aspects of native tissues. This article presents a comprehensive overview of enhancing the Resolution of the bioPrinting construct and identifying methods to improve functionalities of bioprinted tissues.In 3D bioPrinting, Printing Resolution represents the deposited material in the x- and y-axes, while dimensionality defines the structural Resolution of printed constructs. Dimensionality in 3D bioPrinting can be defined as the Resolution in the z-axis. The Printing Resolution, together with dimensionality, contributes to the overall shape fidelity of the bioprinted constructs. The in-depth understanding of physical processes for different Printing technologies is imperative in controlling the print Resolution and definition. In this article, bioPrinting technologies are classified according to the physical processes that deposit or form the bioprinted construct. Due to the different fabrication processes in forming fundamental printed units (voxels), the definition of printability differs for each bioPrinting technique. Another aspect of Resolution is the spatial positioning of cells within each fundamental building unit. The proximity of cells in the bioprinted construct affects the physiological outcom...

  • 3D Printing and BioPrinting in MEMS Technology
    Micromachines, 2017
    Co-Authors: Chee Kai Chua, Wai Yee Yeong, Jia An
    Abstract:

    3D Printing and bioPrinting have advanced significantly in Printing Resolution in recent years, which presents a great potential for fabricating small and complex features suitable for microelectromechanical systems (MEMS) with new functionalities. This special issue aims to give a glimpse into the future of this research field.

  • Characterization and evaluation of 3D printed microfluidic chip for cell processing
    Microfluidics and Nanofluidics, 2016
    Co-Authors: Jia Min Lee, Meng Zhang, Wai Yee Yeong
    Abstract:

    Microfluidics has found ubiquitous presence in biological applications such as tissue spheroid fabrication and pharmacology investigation. The increasing prevalence and complexity demand a highly adaptable fabrication method for the rapid and convenient production of these microfluidic systems. 3D Printing, as an emerging fabrication technique, was investigated in this paper. Microfluidic features were fabricated using two most widely used 3D Printing technologies namely the inkjet Printing and filament deposition techniques. The Printing Resolution, accuracy, repeatability, surface roughness, wetting ability, and biocompatibility of the printed microfluidic chips were characterized. The capability of 3D Printing was demonstrated by Printing a number of microfluidic devices such as rotational flow device and gradient generator. Results showed that 3D Printing techniques were successful in making intricate microscale architectures and have the potential of greatly simplifying the manufacturing process.

François Cayre - One of the best experts on this subject based on the ideXlab platform.

  • WIFS - Towards a realistic channel model for security analysis of authentication using graphical codes
    2013 IEEE International Workshop on Information Forensics and Security (WIFS), 2013
    Co-Authors: Cléo Baras, François Cayre
    Abstract:

    Graphical codes resemble very much the well-known QR-codes, although they are used in a very different application scenario: authenticating and tracing physical goods on which they are printed with small dimensions so as to become uncloneable. In this paper, we propose a security analysis of such codes based on a realistic channel model. We show that the security level of such codes heavily depends on the Printing Resolution. For the first time, our experimental setup enables to assess the maximum number of graphical codes to be safely printed until a security breach occur in the authentication system.

  • Towards a realistic channel model for security analysis of authentication using graphical codes
    2013 IEEE International Workshop on Information Forensics and Security (WIFS), 2013
    Co-Authors: Cléo Baras, François Cayre
    Abstract:

    Graphical codes resemble very much the well-known QR-codes, although they are used in a very different application scenario: authenticating and tracing physical goods on which they are printed with small dimensions so as to become uncloneable. In this paper, we propose a security analysis of such codes based on a realistic channel model. We show that the security level of such codes heavily depends on the Printing Resolution. For the first time, our experimental setup enables to assess the maximum number of graphical codes to be safely printed until a security breach occur in the authentication system.

Stefano Turri - One of the best experts on this subject based on the ideXlab platform.

  • 3D Printing of Cantilever-Type Microstructures by Stereolithography of Ferromagnetic Photopolymers.
    ACS Applied Materials & Interfaces, 2016
    Co-Authors: Caterina Credi, Alessandro Fiorese, Marco Tironi, Luca Magagnin, Roberto Bernasconi, Marinella Levi, Stefano Turri
    Abstract:

    In the present work, prototypes of polymeric cantilever-based magnetic microstructures were fabricated by means of stereolithography (SL). To this end, a UV-curable system suitable for high-Resolution SL-processing was formulated by blending a bifunctional acrylic monomer with photoinitiator and visible dye whose content was tuned to tailor resin SL sensitivity. Subsequently, to confer ferromagnetic properties to the photopolymer, two different strategies were implemented. A two-step approach involved selective deposition of a metal layer on photopolymer SL-cured surfaces through an electroless plating process. On the other hand, SL-processable ferromagnetically responsive nanocomposites (FRCs) were obtained by directly loading magnetite nanoparticles within the photopolymer matrix. In order to achieve high-Printing Resolution, resin SL sensitivities were studied as a function of the various additives contents. Photocalorimetric analyses were also performed to investigate the photopolymer conversion effic...

  • 3D Printing of Cantilever-Type Microstructures by Stereolithography of Ferromagnetic Photopolymers
    ACS Applied Materials and Interfaces, 2016
    Co-Authors: Caterina Credi, Alessandro Fiorese, Marco Tironi, Luca Magagnin, Roberto Bernasconi, Marinella Levi, Stefano Turri
    Abstract:

    In the present work, prototypes of polymeric cantilever-based magnetic microstructures were fabricated by means of stereolithography (SL). To this end, a UV-curable system suitable for high-Resolution SL-processing was formulated by blending a bifunctional acrylic monomer with photoinitiator and visible dye whose content was tuned to tailor resin SL sensitivity. Subsequently, to confer ferromagnetic properties to the photopolymer, two different strategies were implemented. A two-step approach involved selective deposition of a metal layer on photopolymer SL-cured surfaces through an electroless plating process. On the other hand, SL-processable ferromagnetically responsive nanocomposites (FRCs) were obtained by directly loading magnetite nanoparticles within the photopolymer matrix. In order to achieve high-Printing Resolution, resin SL sensitivities were studied as a function of the various additives contents. Photocalorimetric analyses were also performed to investigate the photopolymer conversion efficiency upon light exposure. High-performing formulations were characterized by reduced penetration depth (