scholarly journals Four-Dimensional Printing: Design and Fabrication of Smooth Curved Surface Using Controlled Self-Folding

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Dongping Deng ◽  
Tsz-Ho Kwok ◽  
Yong Chen
Keyword(s):  
Active Material ◽  
Three Dimensional ◽  
Thermal Response ◽  
Curved Surfaces ◽  
4D Printing ◽  
Planar Surfaces ◽  
The Relationship ◽  
Two Sides ◽  
Dimensional Printing ◽  
Printing Method

Traditional origami structures fold along predefined hinges, and the neighboring facets of the hinges are folded to transform planar surfaces into three-dimensional (3D) shapes. In this study, we present a new self-folding design and fabrication approach that has no folding hinges and can build 3D structures with smooth curved surfaces. This four-dimensional (4D) printing method uses a thermal-response control mechanism, where a thermo shrink film is used as the active material and a photocurable material is used as the constraint material for the film. When the structure is heated, the two sides of the film will shrink differently due to the distribution of the constraint material on the film. Consequently, the structure will deform over time to a 3D surface that has no folding hinges. By properly designing the coated constraint patterns, the film can be self-folded into different shapes. The relationship between the constraint patterns and their correspondingly self-folded surfaces has been studied in the paper. Our 4D printing method presents a simple approach to quickly fabricate a 3D shell structure with smooth curved surfaces by fabricating a structure with accordingly designed material distribution.

4D Printing: Design and Fabrication of 3D Shell Structures With Curved Surfaces Using Controlled Self-Folding

2015 ◽  
Author(s):  
Dongping Deng ◽  
Yong Chen
Keyword(s):  
Active Material ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Curved Surfaces ◽  
4D Printing ◽  
Thermally Responsive ◽  
Different Shapes ◽  
New Applications ◽  
Future Work ◽  
Two Sides

Self-folding structures such as origami-based structures have been studied by artists, mathematicians and engineers. New applications are emerging in fields such as biomedical and electronics. Self-folding structures can potentially extend three-dimensional (3D) printing into four-dimensional (4D) printing by intelligently designed material distribution in order to achieve controlled shape deformation over time. Traditionally, self-folding structures are folded along pre-defined hinges such that neighboring facets can transform their shapes. In this study, we present a new design and fabrication approach of self-folding structures with no foldable hinges. A significant benefit is its capability in fabricating shapes with smooth curved surfaces. Our self-folding method is based on a thermally responsive mechanism, where a thermal responsive film is used as the active material while another polymer material coated on the film is used as the constraining material. When the structure is heated, the two sides of the film will shrink differently due to the constraining material. Consequently the structure will fold. By changing the constraining patterns and coated material properties, the film can be self-folded into different shapes. Three types of folding features are presented in our study. Based on them, an unfolding algorithm is presented for a given shell structure with curved surfaces. Theoretical analysis and experimental tests are presented to demonstrate the capability of the self-folding method. Its limitation and future work are also discussed.

BROADSIDE REFRACTION SHOOTING

Geophysics ◽  
1959 ◽  
Vol 24 (4) ◽  
pp. 725-748 ◽  
Author(s):  
T. C. Richards
Keyword(s):  
Approximate Method ◽  
Three Dimensional ◽  
Field Work ◽  
Significant Error ◽  
Curved Surfaces ◽  
Travel Times ◽  
The Relationship

The three‐dimensional refraction trajectories and travel times in seismic broadside refraction shooting across simple steeply dipping or faulted hypothetical structures are determined when the shotpoint is displaced from the axis. No curved surfaces are assumed and the diffractions to be expected from the structural discontinuities are evaluated. An approximate method for correcting arc time measurements taken over the opposite side to that of the shotpoint is investigated while the conversion of times to dip is discussed. Discussion is also given to the differences in the diffraction time curves caused by changing the shotpoint from the up to the down side of a fault and the relationship these curves have with the refraction time curves in both arc and broadside shooting. The results of these studies indicate the care that should be taken in distinguishing between refracted and diffracted events, and in relating a measured broadside time to a particular point on the refractor. The latter may lead to significant error when simple mid‐point depth computations, often resorted to in field work, are employed.

ANALYSIS OF AN EXPERIMENT TO CREATE CURRENT-CARRYING DEVICES FOR PRINTED CIRCUIT BOARDS

2020 ◽  
Vol 13 (2) ◽  
pp. 77-84
Author(s):  
Nikita Yur'ev ◽  
V. Lavlinskiy ◽  
Nadezhda Bokareva
Keyword(s):  
Experimental Data ◽  
Printed Circuit Boards ◽  
Three Dimensional ◽  
Conductive Ink ◽  
Circuit Boards ◽  
Three Dimensional Printing ◽  
Printed Circuit ◽  
Advantages And Disadvantages ◽  
The Relationship ◽  
Dimensional Printing

The article analyzes the properties of conductive inks and substrates for their application. Experimental data reflecting the relationship between the chemical composition and physical properties of the ink solution are shown. The properties of electrical conductivity and ease of application to the substrate are described. This article presents a combination of filler and binder solutions in conjunction with the production technology of conductive ink. The advantages and disadvantages of various combinations of solutions and their application for further three-dimensional formation of boards are evaluated. The article describes the behavior of polymer solutions for use in existing three-dimensional printing technologies.

Geometry-Driven Finite Element for Four-Dimensional Printing

2017 ◽  
Author(s):  
Tsz-Ho Kwok
Keyword(s):  
Finite Element ◽  
Optimization Problem ◽  
Geometric Optimization ◽  
Reserve Design ◽  
The Finite Element Method ◽  
4D Printing ◽  
Shape Transformation ◽  
The Common ◽  
The Relationship ◽  
Dimensional Printing

Four-dimensional (4D) printing is a new category of printing that expands the fabrication process to include time as the forth dimension, and its process planning and simulation have to take time into consideration as well. The common tool to estimating the behavior of a deformable object is the finite element method (FEM). Although FEM is powerful, there are various sources of deformation from hardware, environment, and process, just to name a few, which are too complex to model by FEM. This paper introduces Geometry-Driven Finite Element (GDFE) as a solution to this problem. Based on the study on geometry changes, the deformation principles can be drawn to predict the relationship between the 4D-printing process and the shape transformation. Similar to FEM, the design domain is subdivided into a set of GDFEs, and the principles are applied on each GDFE, which are then assembled to a larger system that describes the overall shape. The proposed method converts the complex sources of deformation to a geometric optimization problem, which is intuitive and effective. The usages and applications of the GDFE framework have also been presented in this paper, including freeform design, reserve design, and design validation.

scholarly journals Design of urban furniture to enhance the soundscape: A case study

2018 ◽  
Vol 25 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Gioia Fusaro ◽  
Francesco D’Alessandro ◽  
Giorgio Baldinelli ◽  
Jian Kang
Keyword(s):  
Three Dimensional ◽  
Experimental Tests ◽  
Open Spaces ◽  
Three Dimensional Printing ◽  
Historical Heritage ◽  
Environmental Feasibility ◽  
The Relationship ◽  
Dimensional Printing

In modern urban scenarios, all the aspects of the historical heritage, including public open spaces and ancient buildings, have to meet the high increase of density of infrastructures and constructions, with the consequent change of visual and sound environments. This in turn affects people’s quality of life. Because of the growing interest on this problem, this study investigates the relationship between soundscape and design solutions for urban furniture, considering technical and environmental feasibility of the designing process, from the materials characteristics, to the acoustic and psychoacoustic impact of the tool on the user. The process includes the acoustic suitability of three-dimensional printing materials, the suitability of acoustic design using software simulation, the experimental assessment of the performance of the three-dimensional printed prototype and the statistical evaluation of the chosen studying parameters and conditions. This article describes all the stages of the designing process, with a focus on the study of shapes and volumes of the prototype and on its impact on the user’s perception. FEM simulations and experimental tests performed in a semi-anechoic chamber allowed to validate the design process. These analyses proved that the designed prototype of urban furniture can not only positively influence the physical environment but also the psychoacoustic perception of it.

A novel fast disintegrating tablet fabricated by three‐dimensional printing

2009 ◽  
Vol 00 (00) ◽  
pp. 090730035508060-7
Author(s):  
Deng-Guang Yu ◽  
Chris Branford-White ◽  
Yi-Cheng Yang ◽  
Li-Min Zhu ◽  
Edward William Welbeck ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Fast Disintegrating Tablet ◽  
Dimensional Printing

Central ossifying fibroma of mandible

2020 ◽  
Vol 13 (12) ◽  
pp. e239286
Author(s):  
Kumar Nilesh ◽  
Prashant Punde ◽  
Nitin Shivajirao Patil ◽  
Amol Gautam
Keyword(s):  
Fibrous Tissue ◽  
Three Dimensional ◽  
Facial Asymmetry ◽  
Ossifying Fibroma ◽  
Mandible Reconstruction ◽  
Three Dimensional Printing ◽  
Osseous Lesion ◽  
Large Size ◽  
Dimensional Printing

Ossifying fibroma (OF) is a rare, benign, fibro-osseous lesion of the jawbone characterised by replacement of the normal bone with fibrous tissue. The fibrous tissue shows varying amount of calcified structures resembling bone and/or cementum. The central variant of OF is rare, and shows predilection for mandible among the jawbone. Although it is classified as fibro-osseous lesion, it clinically behaves as a benign tumour and can grow to large size, causing bony swelling and facial asymmetry. This paper reports a case of large central OF of mandible in a 40-year-old male patient. The lesion was treated by segmental resection of mandible. Reconstruction of the surgical defect was done using avascular fibula bone graft. Role of three-dimensional printing of jaw and its benefits in surgical planning and reconstruction are also highlighted.

Sign in / Sign up

Export Citation Format

Share Document