scholarly journals Control-Based 4D Printing: Adaptive 4D-Printed Systems

2020 ◽  
Vol 10 (9) ◽  
pp. 3020 ◽  
Author(s):  
Ali Zolfagharian ◽  
Akif Kaynak ◽  
Mahdi Bodaghi ◽  
Abbas Z. Kouzani ◽  
Saleh Gharaie ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Advanced Manufacturing ◽  
Wearable Electronics ◽  
Stimuli Responsive ◽  
4D Printing ◽  
Control Units ◽  
Printed Sensors ◽  
3D Printed ◽  
Dynamic Structures ◽  
And Control

Building on the recent progress of four-dimensional (4D) printing to produce dynamic structures, this study aimed to bring this technology to the next level by introducing control-based 4D printing to develop adaptive 4D-printed systems with highly versatile multi-disciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics and other industries such as agriculture and microfluidics. This study introduced and analysed adaptive 4D-printed systems with an advanced manufacturing approach for developing stimuli-responsive constructs that organically adapted to environmental dynamic situations and uncertainties as nature does. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This paper demonstrates the adaptivity of these systems via a combination of proprioceptive sensory feedback, modeling and controllers, as well as the challenges and future opportunities they present.

scholarly journals 3D Printed Chromophoric Sensors

Chemosensors ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 317
Author(s):  
Zachary Brounstein ◽  
Jarrod Ronquillo ◽  
Andrea Labouriau
Keyword(s):  
Thermal Stability ◽  
3D Printing ◽  
Material Properties ◽  
Chemical Structure ◽  
Elevated Temperatures ◽  
Advanced Manufacturing ◽  
Color Changes ◽  
Printed Sensors ◽  
3D Printed ◽  
Manufacturing Techniques

Eight chromophoric indicators are incorporated into Sylgard 184 to develop sensors that are fabricated either by traditional methods such as casting or by more advanced manufacturing techniques such as 3D printing. The sensors exhibit specific color changes when exposed to acidic species, basic species, or elevated temperatures. Additionally, material properties are investigated to assess the chemical structure, Shore A Hardness, and thermal stability. Comparisons between the casted and 3D printed sensors show that the sensing devices fabricated with the advanced manufacturing technique are more efficient because the color changes are more easily detected.

4D Printing of Complex Ceramic Structures via Controlling Zirconia Contents and Patterns

2021 ◽  
Author(s):  
Zhicheng Rong ◽  
Chang Liu ◽  
Yingbin Hu
Keyword(s):  
3D Printing ◽  
Shape Memory ◽  
Shape Change ◽  
Three Dimensional ◽  
Ceramic Materials ◽  
Full Potential ◽  
Sintering Process ◽  
4D Printing ◽  
3D Printed ◽  
Dynamic Components

Abstract In recent years, more and more attentions have been attracted on integrating three-dimensional (3D) printing with fields (such as magnetic field) or innovating new methods to reap the full potential of 3D printing in manufacturing high-quality parts and processing nano-scaled composites. Among all of newly innovated methods, four-dimensional (4D) printing has been proved to be an effective way of creating dynamic components from simple structures. Common feeding materials in 4D printing include shape memory hydrogels, shape memory polymers, and shape memory alloys. However, few attempts have been made on 4D printing of ceramic materials to shape ceramics into intricate structures, owing to ceramics’ inherent brittleness nature. Facing this problem, this investigation aims at filling the gap between 4D printing and fabrication of complex ceramic structures. Inspired by swelling-and-shrinking-induced self-folding, a 4D printing method is innovated to add an additional shape change of ceramic structures by controlling ZrO2 contents and patterns. Experimental results evidenced that by deliberately controlling ZrO2 contents and patterns, 3D-printed ceramic parts would undergo bending and twisting during the sintering process. To demonstrate the capabilities of this method, more complex structures (such as a flower-like structure) were fabricated. In addition, functional parts with magnetic behaviors were 4D-printed by incorporating iron into the PDMS-ZrO2 ink.

scholarly journals Grayscale digital light processing 3D printing for highly functionally graded materials

2019 ◽  
Vol 5 (5) ◽  
pp. eaav5790 ◽  
Author(s):  
Xiao Kuang ◽  
Jiangtao Wu ◽  
Kaijuan Chen ◽  
Zeang Zhao ◽  
Zhen Ding ◽  
...  
Keyword(s):  
3D Printing ◽  
Functionally Graded Materials ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Advanced Manufacturing ◽  
4D Printing ◽  
Poor Control ◽  
Graded Materials ◽  
Digital Light Processing ◽  
Direct Fabrication

Three-dimensional (3D) printing or additive manufacturing, as a revolutionary technology for future advanced manufacturing, usually prints parts with poor control of complex gradients for functional applications. We present a single-vat grayscale digital light processing (g-DLP) 3D printing method using grayscale light patterns and a two-stage curing ink to obtain functionally graded materials with the mechanical gradient up to three orders of magnitude and high resolution. To demonstrate the g-DLP, we show the direct fabrication of complex 2D/3D lattices with controlled buckling and deformation sequence, negative Poisson’s ratio metamaterial, presurgical models with stiffness variations, composites for 4D printing, and anti-counterfeiting 3D printing.

Frontally polymerizable shape memory polymer for 3D printing of free-standing structures

2021 ◽  
Author(s):  
Yongsan An ◽  
Joon Hyeok Jang ◽  
Ji Ho Youk ◽  
Woong-Ryeol Yu
Keyword(s):  
Shape Memory ◽  
Memory Performance ◽  
Shape Memory Polymer ◽  
Three Dimensional ◽  
Frontal Polymerization ◽  
4D Printing ◽  
Free Standing ◽  
Time Shape ◽  
Standing Structure ◽  
3D Printed

Abstract Four-dimensional (4D) printing is used to describe three-dimensional (3D)-printed objects with properties that change over time. Shape memory polymers (SMPs) are representative materials for 4D printing technologies. The ability to print geometrically complex, free-standing forms with SMPs is crucial for successful 4D printing. In this study, an SMP capable of frontal polymerization featuring exothermic self-propagation was synthesized by adding cyclooctene to a poly(dicyclopentadiene) network, resulting in switching segments. The rheological properties of this SMP were controlled by adjusting incubation time. A nozzle system was designed such that the SMP could be printed with simultaneous polymerization to yield a free-standing structure. The printing speed was set to 3 cm/min according to the frontal polymerization speed. A free-standing, hexagonal spiral was successfully printed and printed spiral structure showed excellent shape memory performance with a fixity ratio of about 98% and a recovery ratio of 100%, thereby demonstrating the 3D printability and shape memory performance of frontally polymerizable SMPs.

3D Printing and Growth Induced Bending based on PET-RAFT Polymerization

2020 ◽  
Author(s):  
Chris Bainbridge ◽  
Kyle Engel ◽  
Jianyong Jin
Keyword(s):  
3D Printing ◽  
Surface Properties ◽  
Raft Polymerization ◽  
Advanced Manufacturing ◽  
3D Printer ◽  
4D Printing ◽  
Printing Process ◽  
Raft Agent ◽  
3D Printed ◽  
First Time

4D printing has steadily become an emerging area of advanced manufacturing research and has produced some truly fantastic innovations. Previously we have demonstrated the 3D printing process based on PET-RAFT polymerization, and its subsequent capability in the post-production modification of surface properties. In this work, (1) we further optimized the PET-RAFT 3D printing formulation by replacing RAFT agent CDTPA with BTPA and adjusting the monomers composition; (2) we also observed the photodegradation of the photocatalysts EB and EY under 405nm light and the effects this has on 3D printing; (3) we then did successful 3D printing using a commercial 405nm DLP 3D printer, with an improved build speed of up to 2286 µm/hr; (4) lastly, for the first time we have demonstrated a method for growth induced bending of a 3D printed strip, where the growth on one side of the strip causes stress and the strip bends accordingly to reach a more comfortable position.

Design, Analysis, Experimentation, and Control of a Partially Compliant Bistable Mechanism

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Ayse Tekes ◽  
Hongkuan Lin ◽  
Kevin McFall
Keyword(s):  
Dynamic Response ◽  
Elliptic Integral ◽  
Three Dimensional ◽  
Design Analysis ◽  
Lumped Parameter Model ◽  
Lumped Parameter ◽  
Rigid Body Model ◽  
3D Printed ◽  
Bistable Mechanism ◽  
And Control

Abstract This study presents the design analysis and development of a novel partially compliant bistable mechanism. Motion behavior dependence on links and relative angles are analyzed, lumped parameter model is derived, mechanism parts including the compliant members are three-dimensional (3D) printed and a state feedback controller is implemented so that the slider follows a well-defined trajectory if designed as an actuator. The proposed mechanism consists of initially straight, large deflecting fixed-pinned compliant links, rigid links, and a sliding mass. Dynamic response of the mechanism is studied using elliptic integral solutions, pseudo rigid body model (PRBM), vector closure loop equations and Elliptic integrals. Nonlinear model is simulated in matlab simulink using fourth‐order Runge‐Kutta algorithms. The research emphasizes on the realization and dynamic response of the mechanism and the trajectory control of the slider so that the slider can be kept constant at specified distances resulting a dwell motion if designed as a linear actuator.

scholarly journals Three-Dimensional (3D) Printed Microneedles for Microencapsulated Cell Extrusion

2018 ◽  
Vol 5 (3) ◽  
pp. 59 ◽  
Author(s):  
Chantell Farias ◽  
Roman Lyman ◽  
Cecilia Hemingway ◽  
Huong Chau ◽  
Anne Mahacek ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Root Mean Square Roughness ◽  
Great Promise ◽  
Hollow Microneedle ◽  
Alginate Capsules ◽  
Significant Difference ◽  
Time In Literature ◽  
3D Printed ◽  
And Control ◽  
Cell Extrusion

Cell-hydrogel based therapies offer great promise for wound healing. The specific aim of this study was to assess the viability of human hepatocellular carcinoma (HepG2) cells immobilized in atomized alginate capsules (3.5% (w/v) alginate, d = 225 µm ± 24.5 µm) post-extrusion through a three-dimensional (3D) printed methacrylate-based custom hollow microneedle assembly (circular array of 13 conical frusta) fabricated using stereolithography. With a jetting reliability of 80%, the solvent-sterilized device with a root mean square roughness of 158 nm at the extrusion nozzle tip (d = 325 μm) was operated at a flowrate of 12 mL/min. There was no significant difference between the viability of the sheared and control samples for extrusion times of 2 h (p = 0.14, α = 0.05) and 24 h (p = 0.5, α = 0.05) post-atomization. Factoring the increase in extrusion yield from 21.2% to 56.4% attributed to hydrogel bioerosion quantifiable by a loss in resilience from 5470 (J/m3) to 3250 (J/m3), there was no significant difference in percentage relative payload (p = 0.2628, α = 0.05) when extrusion occurred 24 h (12.2 ± 4.9%) when compared to 2 h (9.9 ± 2.8%) post-atomization. Results from this paper highlight the feasibility of encapsulated cell extrusion, specifically protection from shear, through a hollow microneedle assembly reported for the first time in literature.

scholarly journals Bioresorbable Polymers: Advanced Materials and 4D Printing for Tissue Engineering

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 563
Author(s):  
Sybele Saska ◽  
Livia Pilatti ◽  
Alberto Blay ◽  
Jamil Awad Shibli
Keyword(s):  
Tissue Engineering ◽  
Smart Materials ◽  
Morphological Changes ◽  
New Technology ◽  
Three Dimensional ◽  
Advanced Materials ◽  
Stimuli Responsive ◽  
4D Printing ◽  
Responsive Materials ◽  
Bioresorbable Polymers

Three-dimensional (3D) printing is a valuable tool in the production of complexes structures with specific shapes for tissue engineering. Differently from native tissues, the printed structures are static and do not transform their shape in response to different environment changes. Stimuli-responsive biocompatible materials have emerged in the biomedical field due to the ability of responding to other stimuli (physical, chemical, and/or biological), resulting in microstructures modifications. Four-dimensional (4D) printing arises as a new technology that implements dynamic improvements in printed structures using smart materials (stimuli-responsive materials) and/or cells. These dynamic scaffolds enable engineered tissues to undergo morphological changes in a pre-planned way. Stimuli-responsive polymeric hydrogels are the most promising material for 4D bio-fabrication because they produce a biocompatible and bioresorbable 3D shape environment similar to the extracellular matrix and allow deposition of cells on the scaffold surface as well as in the inside. Subsequently, this review presents different bioresorbable advanced polymers and discusses its use in 4D printing for tissue engineering applications.

scholarly journals Light activation of 3D-printed structures: from millimeter to sub-micrometer scale

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Hoon Yeub Jeong ◽  
Soo-Chan An ◽  
Young Chul Jun
Keyword(s):  
Smart Materials ◽  
Structural Changes ◽  
Three Dimensional ◽  
Light Activation ◽  
4D Printing ◽  
Comprehensive Review ◽  
Functional Changes ◽  
Active Devices ◽  
3D Printed ◽  
Micrometer Scale

Abstract Three-dimensional (3D) printing enables the fabrication of complex, highly customizable structures, which are difficult to fabricate using conventional fabrication methods. Recently, the concept of four-dimensional (4D) printing has emerged, which adds active and responsive functions to 3D-printed structures. Deployable or adaptive structures with desired structural and functional changes can be fabricated using 4D printing; thus, 4D printing can be applied to actuators, soft robots, sensors, medical devices, and active and reconfigurable photonic devices. The shape of 3D-printed structures can be transformed in response to external stimuli, such as heat, light, electric and magnetic fields, and humidity. Light has unique advantages as a stimulus for active devices because it can remotely and selectively induce structural changes. There have been studies on the light activation of nanomaterial composites, but they were limited to rather simple planar structures. Recently, the light activation of 3D-printed complex structures has attracted increasing attention. However, there has been no comprehensive review of this emerging topic yet. In this paper, we present a comprehensive review of the light activation of 3D-printed structures. First, we introduce representative smart materials and general shape-changing mechanisms in 4D printing. Then, we focus on the design and recent demonstration of remote light activation, particularly detailing photothermal activations based on nanomaterial composites. We explain the light activation of 3D-printed structures from the millimeter to sub-micrometer scale.

scholarly journals Effects of Topology Optimization in Multimaterial 3D Bioprinting of Soft Actuators

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Ali Zolfagharian ◽  
Martin Denk ◽  
Abbas Z. Kouzani ◽  
Bodaghi Bodaghi ◽  
Saeid Nahavandi ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Stimuli Responsive ◽  
Bending Performance ◽  
Stimuli Responsive Polymers ◽  
Potential Applications ◽  
Dynamic Structures ◽  
Soft Actuators

Recently, there has been a proliferation of soft robots and actuators that exhibit improved capabilities and adaptability through three-dimensional (3D) bioprinting. Flexibility and shape recovery attributes of stimuli-responsive polymers as the main components in the production of these dynamic structures enable soft manipulations in fragile environments, with potential applications in biomedical and food sectors. Topology optimization (TO), when used in conjunction with 3D bioprinting with optimal design features, offers new capabilities for efficient performance in compliant mechanisms. In this paper, multimaterial TO analysis is used to improve and control the bending performance of a bioprinted soft actuator with electrolytic stimulation. The multimaterial actuator performance is evaluated by the amplitude and rate of bending motion and compared with the single material printed actuator. The results demonstrated the efficacy of multimaterial 3D bioprinting optimization for the rate of actuation and bending.

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