scholarly journals 3D printed deformable sensors

2020 ◽  
Vol 6 (25) ◽  
pp. eaba5575 ◽  
Author(s):  
Zhijie Zhu ◽  
Hyun Soo Park ◽  
Michael C. McAlpine
Keyword(s):  
3D Printing ◽  
Target Surface ◽  
Wearable Electronics ◽  
Impedance Tomography ◽  
Direct Printing ◽  
System A ◽  
Biological Surface ◽  
Benefit Patient ◽  
Printing System ◽  
3D Printed

The ability to directly print compliant biomedical devices on live human organs could benefit patient monitoring and wound treatment, which requires the 3D printer to adapt to the various deformations of the biological surface. We developed an in situ 3D printing system that estimates the motion and deformation of the target surface to adapt the toolpath in real time. With this printing system, a hydrogel-based sensor was printed on a porcine lung under respiration-induced deformation. The sensor was compliant to the tissue surface and provided continuous spatial mapping of deformation via electrical impedance tomography. This adaptive 3D printing approach may enhance robot-assisted medical treatments with additive manufacturing capabilities, enabling autonomous and direct printing of wearable electronics and biological materials on and inside the human body.

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

scholarly journals Off-Axis Diffractive Optics for Compact Terahertz Detection Setup

2020 ◽  
Vol 10 (23) ◽  
pp. 8594
Author(s):  
Paweł Komorowski ◽  
Mateusz Surma ◽  
Michał Walczakowski ◽  
Przemysław Zagrajek ◽  
Agnieszka Siemion
Keyword(s):  
3D Printing ◽  
Small Volume ◽  
Optical Element ◽  
Structure Design ◽  
Thz Radiation ◽  
Direct Printing ◽  
Terahertz Detection ◽  
3D Printed ◽  
Printing Techniques ◽  
Optical Structure

Medical and many other applications require small-volume setups enabling terahertz imaging. Therefore, we aim to develop a device for the in-reflection examination of the samples. Thus, in this article, we focus on the diffractive elements for efficient redirection and focusing of the THz radiation. A terahertz diffractive optical structure has been designed, optimized, manufactured (using extrusion-based 3D printing) and tested. Two manufacturing methods have been used—direct printing of the structures from PA12, and casting of the paraffin structures out of 3D-printed molds. Also, the limitations of the off-axis focusing have been discussed. To increase the efficiency, an iterative algorithm has been proposed that optimizes off-axis structures to focus the radiation into small focal spots located far from the optical axis, at an angle of more than 30 degrees. Moreover, the application of higher-order kinoform structure design allowed the maintaining of the smallest details of the manufactured optical element, using 3D printing techniques.

scholarly journals Optimization of the Formulation and Properties of 3D-Printed Complex Egg White Protein Objects

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 164 ◽  
Author(s):  
Lili Liu ◽  
Xiaopan Yang ◽  
Bhesh Bhandari ◽  
Yuanyuan Meng ◽  
Sangeeta Prakash
Keyword(s):  
3D Printing ◽  
Rheological Properties ◽  
Sensory Evaluation ◽  
Egg White ◽  
Egg White Protein ◽  
Evaluation Score ◽  
Optimum Formulation ◽  
Printing System ◽  
3D Printed ◽  
New Formulation

The 3D printing of foods is an emerging technique for producing unique and complex food items. This study presents the optimization of a new formulation for 3D printing foods on the basis of a complex system, which contains egg white protein (EWP), gelatin, cornstarch, and sucrose. The effects of different formulations on the rheological properties and the microstructure of the printing system were investigated. The formulation was optimized through response surface methodology, and a central composite design was adopted. The optimum formulation of the 3D mixture printing system was made of gelatin (14.27 g), cornstarch (19.72 g), sucrose (8.02 g), and EWP (12.98 g) in 250 mL of total deionized water with a maximum sensory evaluation score of 34.47 ± 1.02 and a viscosity of 1.374 ± 0.015 Pa·s. Results showed that the viscosity of the formulation correlated with the sensory evaluation score. The rheological properties and tribological behavior of the optimum formulation significantly differed from those of other formulations. A viscosity of 1.374 Pa·s supported the timely flow out of the printing material from the nozzle assisting 3D printability. Thus, 3D printing based on the egg white protein mixture system is a promising method for producing complex-shaped food objects.

On the Crosstalks between a Pair of Transmission Lines in the Presence of a 3D Printed Electrifi Trace

2021 ◽  
Vol 35 (11) ◽  
pp. 1286-1287
Author(s):  
Dipankar Mitra ◽  
Kazi Kabir ◽  
Jerika Clevelenad ◽  
Ryan Striker ◽  
Benjamin Braaten ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Comparative Study ◽  
Transmission Lines ◽  
Electromagnetic Compatibility ◽  
Physical Contact ◽  
Wearable Electronics ◽  
Conductive Filament ◽  
3D Printed ◽  
Microstrip Transmission Lines

The technology of additive manufacturing results in 3D printing of conductive traces in radio frequency circuits. This creates a plethora of possibilities in realizing flexible and wearable electronics. While the prototypes of microstrip transmission lines and antennas have been recently reported, there is now a need of Electromagnetic Compatibility based study of such 3D printed conductive traces. This paper presents a comparative study on the near end and far end unintentional crosstalk components between a pair of microstrip transmission lines made of Copper in the presence of a 3D printed conductive trace made of a commercially available conductive filament, Electrifi. Any physical contact with the 3D printed trace has been purposefully averted to discard the high contact resistance between the trace and such contacts.

scholarly journals Bone Regeneration Capability of 3D Printed Ceramic Scaffolds

2020 ◽  
Vol 21 (14) ◽  
pp. 4837 ◽  
Author(s):  
Ju-Won Kim ◽  
Byoung-Eun Yang ◽  
Seok-Jin Hong ◽  
Hyo-Geun Choi ◽  
Sun-Ju Byeon ◽  
...  
Keyword(s):  
3D Printing ◽  
Bone Regeneration ◽  
Negative Control Group ◽  
Negative Control ◽  
Control Group ◽  
Digital Light Processing ◽  
Defect Sites ◽  
Significant Difference ◽  
Printing System ◽  
3D Printed

In this study, we evaluated the bone regenerative capability of a customizable hydroxyapatite (HA) and tricalcium phosphate (TCP) scaffold using a digital light processing (DLP)-type 3D printing system. Twelve healthy adult male beagle dogs were the study subjects. A total of 48 defects were created, with two defects on each side of the mandible in all the dogs. The defect sites in the negative control group (sixteen defects) were left untreated (the NS group), whereas those in the positive control group (sixteen defects) were filled with a particle-type substitute (the PS group). The defect sites in the experimental groups (sixteen defects) were filled with a 3D printed substitute (the 3DS group). Six dogs each were exterminated after healing periods of 4 and 8 weeks. Radiological and histomorphometrical evaluations were then performed. None of the groups showed any specific problems. In radiological evaluation, there was a significant difference in the amount of new bone formation after 4 weeks (p < 0.05) between the PS and 3DS groups. For both of the evaluations, the difference in the total amount of bone after 8 weeks was statistically significant (p < 0.05). There was no statistically significant difference in new bone between the PS and 3DS groups in both evaluations after 8 weeks (p > 0.05). The proposed HA/TCP scaffold without polymers, obtained using the DLP-type 3D printing system, can be applied for bone regeneration. The 3D printing of a HA/TCP scaffold without polymers can be used for fabricating customized bone grafting substitutes.

scholarly journals Ultrasensitive Wearable Strain Sensors of 3D Printing Tough and Conductive Hydrogels

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1873 ◽  
Author(s):  
Jilong Wang ◽  
Yan Liu ◽  
Siheng Su ◽  
Junhua Wei ◽  
Syed Rahman ◽  
...  
Keyword(s):  
3D Printing ◽  
Calcium Ions ◽  
Strain Sensors ◽  
Wearable Electronics ◽  
Ionic Conductors ◽  
Hydrogel Film ◽  
Excess Calcium ◽  
3D Printed ◽  
Conductive Hydrogels ◽  
Human Motions

In this study, tough and conductive hydrogels were printed by 3D printing method. The combination of thermo-responsive agar and ionic-responsive alginate can highly improve the shape fidelity. With addition of agar, ink viscosity was enhanced, further improving its rheological characteristics for a precise printing. After printing, the printed construct was cured via free radical polymerization, and alginate was crosslinked by calcium ions. Most importantly, with calcium crosslinking of alginate, mechanical properties of 3D printed hydrogels are greatly improved. Furthermore, these 3D printed hydrogels can serve as ionic conductors, because hydrogels contain large amounts of water that dissolve excess calcium ions. A wearable resistive strain sensor that can quickly and precisely detect human motions like finger bending was fabricated by a 3D printed hydrogel film. These results demonstrate that the conductive, transparent, and stretchable hydrogels are promising candidates as soft wearable electronics for healthcare, robotics and entertainment.

3D Printed Titanium Dioxide Thin Films for Optoelectronic Applications

2020 ◽  
Vol 843 ◽  
pp. 79-83
Author(s):  
Krairop Charoensopa ◽  
Aran Hansuebsai ◽  
Kazuhiro Manseki
Keyword(s):  
Thin Films ◽  
3D Printing ◽  
Dye Sensitized Solar Cells ◽  
Time Operation ◽  
Nozzle Size ◽  
Deposition Modeling ◽  
Printing System ◽  
3D Printed ◽  
Optoelectronic Applications ◽  
Titanium Dioxide Thin Films

This work focused on the printing of semiconductor TiO2 thin films for solar cell applications by 3D printing system. We demonstrate a Liquid Deposition Modeling (LDM) type for controlling the pattern of TiO2 electrode. The advantage of this type of printer is able to vary the numbers of printed layer as well as different levelling pattern of TiO2 thin films by one time operation. Our aim was to study the effects of operating parameters of the 3D printer, such as nozzle size, speed and pressure on the thickness and uniformity of the printed TiO2 films. Using a commercial TiO2 paste, TiO2 precursor films were deposited on a conductive F-doped SnO2 glass by adjusting nozzle size, speed and pressure. The precursor films with different printed layers and levelling pattern were sintered using oven to produce porous TiO2 electrodes. The thickness and surface roughness of obtained TiO2 electrodes were characterized using Scanning Electron Microscope (SEM) and 3D Measuring Laser Microscope. The printed TiO2 substrates were applied to dye-sensitized solar cells as electrodes. Our LDM type 3D printing will provide a new way of levelling design of device components for versatile optoelectronic applications.

scholarly journals Fluctuating Intelligence. Bioinspired 3D Printed Design on Textile

2021 ◽  
Vol 74 (74) ◽  
Author(s):  
Gabriele Pontillo ◽  
Carla Langella
Keyword(s):  
3D Printing ◽  
Design Thinking ◽  
Additive Technologies ◽  
Production Methods ◽  
Direct Printing ◽  
The Past ◽  
New Frontier ◽  
The Future ◽  
3D Printed ◽  
The Relationship

"Since its appearance in the world of design, 3D printing has been acclaimed as a new opportunity to free design thinking from the constraints imposed by traditional production processes. Over the past decade, additive systems have been applied in a variety of cultural and production contexts, crossing the boundaries of industry and beyond the semi-artisan dimension that has long characterized them. If 3D printing is now recognized as one of the production methods of the future, it is necessary to question the next prospects and especially the future of the relationship between design and additive technologies. This paper intends to propose the scenario of the use of additive technologies of direct printing on fabrics as a new frontier of design and production that allows the development of changeable, flexible and composite artifacts increasingly related to the multi-functionality of nature and the human body and increasingly adaptable to the complexity of the needs of contemporary living."

3D printing of geopolymer-based concrete for building applications

2020 ◽  
Vol 26 (10) ◽  
pp. 1783-1788
Author(s):  
Asif Ur Rehman ◽  
Vincenzo M. Sglavo
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Modulus Of Rupture ◽  
Content Type ◽  
Wide Range ◽  
Structural Applications ◽  
Jet Printing ◽  
Printing System ◽  
3D Printed ◽  
Alkali Activated

Purpose Three-dimensional (3D) printing technology allows geometric complexity and customization with a significant reduction in the structural environmental impact. Nevertheless, it poses a serious threat to the environment when organic binders are used. Binder jet printing of alkali-activated geopolymer precursor can represent a successful and environmental-friendly alternative. Design/methodology/approach The present work reports about the successful 3D printing of metakaolin-based alkali-activated concrete, with dimensional integrity and valuable mechanical behavior. Findings The geometric behavior was studied as a function of alkali activator flow rate, and the minimum geometric deviation with complete saturation was recorded at 103 mg/s. The printed specimen is characterized by a modulus of rupture as high as 4.4 MPa at 135 mg/s. Practical implications The 3D printed geopolymer-based concrete can be potentially used in a wide range of structural applications from construction to thermal insulation elements. Originality/value The analysis of the 3D geopolymer-based concrete printing system and material conducted in this paper is original.

Nanoclay Suspension-Enabled Extrusion Bioprinting of 3D Soft Structures

2021 ◽  
pp. 1-29
Author(s):  
Yifei Jin ◽  
Ruitong Xiong ◽  
Patrick Antonelli ◽  
Christopher J. Long ◽  
Christopher W. McAleer ◽  
...  
Keyword(s):  
3D Printing ◽  
Tympanic Membrane ◽  
Solidification Rate ◽  
Three Dimensional ◽  
Glycol Diacrylate ◽  
Direct Printing ◽  
Printing System ◽  
Poly Ethylene ◽  
Extrusion Printing ◽  
3D Printing Technique

Abstract Three-dimensional (3D) extrusion printing of cellular/acellular structures with biocompatible materials has been widely investigated in recent years. However, the requirement of suitable solidification rate of printable ink materials constrains the utilization of extrusion-based 3D printing technique. In this study, the nanoclay yield-stress suspension-enabled extrusion-based 3D printing system has been investigated and demonstrated to overcome solidification rate constraints during printing. Utilizing the liquid-solid transition property of nanoclay suspension, two fabrication approaches, including nanoclay support bath-enabled printing and nanoclay-enabled direct printing, have been proposed. For the former approach, nanoclay (Laponite EP) has been used as a support bath material to fabricate alginate-based tympanic membrane patches. The constituents of alginate-based ink have been investigated to have the desired mechanical property of alginate-based tympanic membrane patches and facilitate the printing process. For the latter approach, nanoclay (Laponite XLG) has been used as an internal scaffold material to help print poly (ethylene glycol) diacrylate (PEGDA)-based neural chambers, which can be further cross-linked in air. Mechanical stress analysis has been performed to explore the geometric limitation of printable Laponite XLG-PEGDA neural chambers.

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