3D Hangouts – Mirrors, NeoPixels and Starships

Live stream starts Wednesday, Janurary 22 2020 at 11am ET.

Learn guide, code and build photos and more

Code on Github

ItsyBitsy nRF52840

Mini Skinny NeoPixel Strip

Lipoly Backpack

500mah Battery

Slide Switch

Roll of mirror film

Acrylic Disc

CircuitPython Downloads: https://circuitpython.org/
https://www.youtube.com/adafruit/live #3DHangouts

3D Parts Library on GitHub

Layer by Layer – Spheres and Cylinder Snap Fits

Timelapse Tuesday:
SpaceX Starship / Super Heavy (BFR 2018) – AliShug

1/22/2020 community makes:
https://www.thingiverse.com/make:753422 mario boo planter
https://www.thingiverse.com/make:752709 kingdom keyblade
https://www.thingiverse.com/make:751313 hypotrochoid card

4D Printing in Singapore: Researchers Pair Compliant Mechanisms with Chitosan Biopolymers

Researchers continue to reach from the 3D realm to the next level, seeking to master the comprehensive fabrication of 4D structures. Now, a team of scientists from Singapore is exploring new ways to create flexible, programmable passive actuators, outlining their findings in the recently published ‘3D Printing of Compliant Passively Actuated 4D Structures.’

For this study, the research team paired compliant mechanisms (CM) with water-responsive chitosan biopolymers. With CM, the scientists were able to take advantage of benefits such as:

  • No hysteresis
  • Compactness
  • Ease of fabrication
  • Simplicity
  • Light weight
  • High reliability
  • Frictionless, wear-free motion

CMs are beneficial today in applications such as:

  • Implants
  • Soft robotics
  • Building structures
  • Space research
  • Micro-engineering

Previous work of chitosan based passive actuator with revolute joints

And while there is a long list of ‘pros’, CMs still offer a host of issues researchers, manufacturers, and industrial users must surpass in terms of both design and fabrication. With additive manufacturing being used in CM manufacturing, the goal is to provide the mechanical force required to spur on movement and possible deformation of the compliant part, which may respond to temperature, light, and moisture. Such products are categorized as 4D or ‘smart materials’ as they are able to respond to their environment accordingly.

Materials such as chitosan, an extremely common polymer, have been used more often with 3D printing, in examples like bioprinting neural tissue. Materials bordering on the 4D have been tested and used many times also with soft robotics, reinforced composites, and more.

Initially, a single design was created for the actuator nodes, with a ‘truss-inspired cantilever fitted with hygroscopic chitosan films.’ Chitosan biopolymers allow for the necessary deformation in this project design, as well as many applications today like textiles, cosmetics, agriculture, bioprinting, and more.

As they began working to create four compliant designs, researchers used cotton gauze to strengthen the chitosan, structuring it into thin pieces of film with a specific solution that is filtered, degassed, and then cast into molds. They put the films through another washing and drying cycle and then began experimenting with their designs, on a mission to make strides in achieving suitable and programmable shape deformation.  In their prototype, the researchers used an ‘intuitive physical’ concept as they investigated several different CM designs to meet the necessary range of motion in a variety of shapes, layer thickness, and more.

The flexure must be compliant enough to deflect 9.34 mm under the load from a
50gm test weight in order to achieve the targeted shape change

Several ‘springy’ designs were developed to spread the load for each flexure, along with allowing for better control with programmable bending in the system. Strength was evaluated also with a load test, and static non-linear structural FEM analysis.

Different springy-derivative flexural designs (a) CMD 1 (b) CMD 2 (c) CMD 3 (d) CMD 4

FEA simulation for four different CM designs (a, b, e & f) Maximum stress (c, d, g & h) Maximum deflection

3D printing of the research project’s actuator was performed on a Stratasys Fortus 450mc FDM 3D printer, using ASA—a propriety model material by Stratasys that is similar to ABS. The team spent 4.5 hours printing the part, and then it was placed in a solution to assist in removal of support materials. In testing, the researchers noted good performance from the actuator, with no signs of mechanical failure at all; however, there were still ‘significant variations from the expected results.’

3D printing of the actuator (a) Sliced model of the actuator before printing (b) Print results of CM Design 3

“The average total deformation between the two states of the actuator was calculated to be 71.2mm, measured by changes in height of the cantilevering end of the actuator. This 71.2 mm represents nearly one-third of the total actuator length, which points to the ability of the CM to accommodate a relatively large range of motion. The expected deformation from 2D simulation was 95.6mm, and so evidently the chitosan did not expand to their 12.8 % capacity as expected,” concluded the researchers.

“It is possible that even though the films lose much of their stiffness when saturated, that there was still insufficient driving force to cause significant mechanical strain of the films. One potential workaround would be to implement another tensile element to the assembly that, when added on top of the assembly’s self-weight, could encourage the full elongation of the chitosan films.”

Comparison of (a) Simulated curve of dry and wet state (b) Physical results of dry and wet state curvature

Comparison of curvature over three cycles (a) Dry state (b) Wet state

What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘3D Printing of Compliant Passively Actuated 4D Structures’]


The post 4D Printing in Singapore: Researchers Pair Compliant Mechanisms with Chitosan Biopolymers appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

HP and NTU Singapore Officially Open Joint Corporate 3D Printing Lab

This week, Nanyang Technological University (NTU) in Singapore officially opened the doors to a new corporate lab that will help manufacturing companies as they work towards adopting digital technology. This new lab, created through a collaboration between the university and HP, will offer a digital manufacturing skills development program for Industry 4.0.

L-R: The HP-NTU Digital Manufacturing Corporate Lab was officially opened by NRF Singapore Executive Director Lim Tuang Liang; NTU Senior Vice President (Research) Prof. Lam Khin Yong; HP Inc CTO Shane Wall; and HP Inc Chief Technologist, Print, Glen Hopkins.

The facility has been dubbed the HP-NTU Digital Manufacturing Corporate Lab, and features a variety of technologies, such as supply chain models that enable faster time to market and intelligent design software tools that automate advanced customization, that will help make manufacturing operations more cost-effective, efficient, and sustainable. Members of tomorrow’s workforce can then become better equipped for work in the future manufacturing industry.

The partnership between the university, HP, and the National Research Foundation Singapore (NRF) was first announced last October, and this new facility is HP’s first university laboratory collaboration in Asia. Using the lab’s intelligent design software tools, engineers will be better able to customize and optimize the mechanical properties of their materials, while the automated technology will allow for designs that use the best combination of these properties so the resulting 3D printed parts have the necessary flexibility, strength, and weight. Then, manufacturers can rapidly scale production of custom goods even when the demand is high.

“HP’s passion for innovation, together with NTU’s world-class research capabilities, allow us to achieve new breakthroughs and unlock new solutions for both business and society,” said Shane Wall, Head of HP Labs and the company’s CTO.

One of NTU and HP’s joint goals is to recruit 100 researchers to work in the new lab, which already employs 60, in order to create new and innovative products. One current research project taking place there is focused on designing and optimizing end-to-end supply chain operations, so that manufacturers can use better business models and analytics to reduce how much time is needed to find parts that may be good candidates for fabricating with 3D printing, and also better measure their impact on the world’s carbon footprint.

This proof-of-concept project, and others, were presented at the opening of the HP-NTU Digital Manufacturing Corporate Lab, along with several technology demonstrations. Additionally, the grand opening was part of HP’s anniversary celebration of 50 years of growing its business in Singapore,

NTU Professor Tan Ming Jen and Dr. Mike Regan, co-directors of the HP-NTU Digital Manufacturing Corporate Lab, holding up 3D printed products from the HP Multi Jet Fusion 3D printer.

In conjunction with opening the new lab, NTU and HP worked together to create six SkillsFuture courses for manufacturing professionals.

“Our joint work in 3D printing, artificial intelligence (AI), machine learning, security and sustainability will produce disruptive technologies that define the future of manufacturing,” stated Wall. “Working together, we can create the workforce of the future and ensure the fourth Industrial Revolution is also a sustainable revolution.”

The skills development program will offer training in additive manufacturing and digital design under SkillsFuture, covering topics like AM fundamentals, automation, user experience, digital product designs, business models, and data management. About 120 workers each year can participate in these courses.

“The advanced technologies and automation solutions jointly developed by NTU and HP are expected to impact businesses in Singapore and beyond, as these innovations are geared towards efficiency, productivity and most importantly, sustainability,” said Professor Lam Khin Yong, NTU’s Senior Vice President of research.

“The new SkillsFuture courses developed jointly with HP also bring valuable industrial perspectives to help upskill and train a critical talent pool for Singapore.

“This will support the country’s drive towards becoming a smart nation as it faces the challenges of the fourth Industrial Revolution.”

Discuss this story and other 3D printing topics at 3DPrintBoard.com or share your thoughts below. 

[Source: The Straits Times / Images: NTU Singapore]

The post HP and NTU Singapore Officially Open Joint Corporate 3D Printing Lab appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Making a Ring With Magic Opaque Acrylic #WearableWednesday #3DPrinting @Chardane #CircuitPython

Shared on Charlyn Gonda’s Blog:

I made a ring! It’s using this special material that looks opaque but it actually lets light shine through beautifully. This was a pretty simple project, and you can do it too!

This Sparkle Ring project uses an Adafruit Gemma M0 with CircuitPython to control a Neopixel Jewel inside a laser cut ring enclosure I designed. It requires some soldering, so it’s great to practice if you’re just starting to learn.

Read more and check out charlyn on Twitter!

Flora breadboard is Every Wednesday is Wearable Wednesday here at Adafruit! We’re bringing you the blinkiest, most fashionable, innovative, and useful wearables from around the web and in our own original projects featuring our wearable Arduino-compatible platform, FLORA. Be sure to post up your wearables projects in the forums or send us a link and you might be featured here on Wearable Wednesday!

A New 3D Printing Method: Tethered Pyro-Electrospinning for 3D Printed Microstructures

Authors Sara Coppola, Giuseppe Nasti, Veronica Vespini, and Pietro Ferraro explore a new technique for 3D printing with biocompatible materials, outlined in ‘Layered 3D Printing by Tethered Pyro-Electrospinning.’ Motivated to overcome current challenges in the fabrication of fibers on both the micro- and nanoscale, the researchers offer a novel 3D printing method with the use of moderate temperatures resulting in both accuracy and flexibility.

Fibers today can be 3D printed for a variety of applications like wearables, custom biomedical devices, drug-delivery systems, bioprinted scaffolds, and more. While electrospinning is already a popular method for creating fibers, pyro-electrohydrodynamic (pyro-EHD) printing can be used for creating polymers fibers while overcoming typical EHD processes which are governed by nozzle size.

This study demonstrates the first use of pyro-EHD methods for creating biodegradable and biocompatible polymers with a variety of geometries and micro-architectures to include:

  • Wall
  • Square
  • Triangle
  • Hybrid structures

Materials used for samples consisted of Poly(lactic-co-glycolic acid) PLGA and dimethyl carbonate, with fluorochrome as an additive to the polymer for use as a model drug. In creating the polymeric fibers, the research team used tethered pyro-electrospinning, activated as a drop of the solution was used as a reservoir and then placed under the LN crystal plate.

“The reservoir drop was directly pipetted over a hydrophobic micropillar made in Polydimethylsiloxane (PDMS) and placed over a commercial microscope glass slide,” explained the researchers. “Under the activation of the TPES process, the droplet started to deform, creating an elongated tip from which fibers were drawn. The target used for the collection was placed in front of the drop and removed at the end of the over-printing procedure.”

Over-printing occurs as an ‘intense pyroelectric field’ emerges from the LN crystal, according to the right temperature. The researchers used the following equipment while engaged in pyro 3D printing:

  • Reservoir solution drop
  • Pyroelectric crystal
  • Thermal control system
  • Programmable stage motion
  • Glass target holder
  • Manual micro-stages with axis control

Once the pyroelectric material reaches a temperature of about 80°, a high electric field is created. High voltage is then charged between the crystal and the plate supporting the drop, with ions gathering within the printing solution—forming chargers.

“The charges would bring an electrostatic force to deform the drop’s meniscus to form a conical shape (Taylor cone),” explain the researchers. “When the electrostatic force will overcome the surface tension at the Taylor cone, a jet would be injected from the meniscus onto the receiving substrate.

“The reservoir droplet is sited in front of the active crystal at a distance h < 1 mm. The selected distance allows preventing the jetting from buckling as it hits the target. In this way, the bending instability and splitting of the charged jet are overcome.”

Outline of the set-up for layered 3D printing: the reservoir drop is sited under the LN crystal heated by a thermal control system. During the experiment, real-time visualization was ensured in order to control at the same time the jetting process and the target position. For the fabrication of layered architecture, the target was moved along the x,y direction. In the top-view the pink trails and the arrows indicate the direction of movement.

Jet diameter relies on:

  • Surface tension
  • Flow rate
  • Dielectric constant
  • Electric current

Plotting varied due to the impacts of ink properties, printing parameters, and temperature.

Fiber characteristics were adjusted during the TPES printing process, with fibers placed on the substrate and microstructures ‘obtained by superimposition.’ The research team noted that three parameters affected fiber diameters, with a temperature of 110°C activating the pyro-electric effect.

“The resulting printed fibers had a diameter (d) ranging between 10 μm <  < 30 μm. Controlling these parameters could be possible to produce fiber of about 1 μm diameter or even less, as demonstrated in case of TPES,” stated the researchers.

Schematic outline of three-dimensional architectures: (a) a single wall freestanding along the direction was constructed by overlay, the blue arrows indicate the direction of printing, (b) a single wall was constructed crossing a matrix of single fibers, creating a sort of square profile where only one side was obtained by superimposition, (c) a cubic architecture was constructed side by side, starting from the fabrication of the first wall (side ) all the adjacent sides were completed in a clockwise direction, and (d, e) cubic and triangular architecture were obtained by overlay of the complete profile, starting from the first track, the same profile was overwritten. The blue arrows indicated the direction of printing.

Pattern models, pre-designed for the study, manipulated motion during each stage, allowing for the layers to be fabricated. A high-resolution stage was necessary for the proper regulation of features and patterns.

The experimental portion of the study involved doping their PLGA/DMC solution with fluorochrome.  Both PLGA and DMC are highly dissolvable, but also biodegradable and attractive for use in this study. Microstructures were fabricated from the initial single wall, serving as a ‘building block’ for future layers of polymeric fibers.

After printing simple walls, the researchers moved on to more complex geometries such as a polymeric grid and a square, with all sides comprised of five layers.

(a) Schematic outline of the experiment. (b) Streomicroscope image of a single wall crossing a matrix of single fibers at the bottom. (c) Close up of the crossing and focus on a crossing point making evident the good control in superimposition (d).

“Following the same procedure for the realization of a regular three-dimensional microstructures we tested a triangular geometry where the angles between the adjacent side are acute ~30°. The construction of the architecture by superimposing the complete profile three times resulted in a good spatial resolution and vertical finishing,” stated the researchers.

(a) Hybrid microstructure made of hemispherical drops and multi-layered fibers. The drops were used as pillars for the construction of a free-standing wall. (b, c) Stereomicroscope image and close up of the sustaining pillars and of the overprinted fibers.

“ … starting from the fabrication of elementary geometry (wall, cubic, and triangular microstructures) this work represents the base for the design of more complex microarchitectures. The fabrication process is described in detail; the fabricated microstructures have been characterized, focusing on the use of composite material and, in particular, of biocompatible and biodegradable biomaterials,” concluded the researchers. “Taken into account that there is a growing demand for novel products and devices such as encapsulation systems, it is easy to imagine that the exploitation of different additive manufacturing approaches could find use in regenerative medicine with a strong interest in the development of in vivo bio-incubators that better replicate the tissue environment.”

3D printed microstructures and architectures continue to be a source of innovation via researchers around the world, involving research for new drug delivery systems, optics, tissue repair, and more.

What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘Layered 3D Printing by Tethered Pyro-Electrospinning’]

The post A New 3D Printing Method: Tethered Pyro-Electrospinning for 3D Printed Microstructures appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

State of the Art: Carbon Fiber 3D Printing, Part Six

One topic we’ve skirted around in our carbon fiber series so far is large-scale composite printing processes. The reason for this is because it is both a big topic, literally and figuratively and involves material mixes that don’t quite fit with the continuous carbon fiber reinforcements we’ve discussed so far.

The BAAM 3D printer. Image courtesy of ORNL.

Oak Ridge National Laboratory (ORNL) is a pioneer in this space because the U.S. Department of Energy Lab almost single-handedly developed the technology, though it did so with the help of public tax dollars and partnerships with companies in the industry. Working with machine manufacturer Cincinnati Incorporated and Local Motors, ORNL developed the first large-scale plastic pellet 3D printer.

The project team used an old experiment additive construction that consisted of a large gantry system meant for extruding concrete. The printer was retrofitted with a screw extruder to process pellets made up of ABS with roughly five percent chopped carbon fiber filler. Using pellets has the advantage of much faster material handling, as well as reduced cost, since these are the same materials made for injection molding. Since injection molding pellets are available in wide supply and don’t need to be further processed into filament, the price is significantly lower.

The result was the Big Area Additive Manufacturing-CI system. The original BAAM-CI system was capable of printing 40 pounds of material per hour in a build volume of 7 ft x 13 ft x 3 ft. To demonstrate the sheer power of the machine, ORNL and its partners have 3D printed the chassis for a number of vehicles, including cars, boats and excavator cabs.

This Shelby Cobra is 3D-printed. Image courtesy of ORNL.

Since the first BAAM-CI printer was used to create a replica Shelby Cobra, its capabilities have grown greatly. Cincinnati Inc. now offers four sizes ranging from 11.7 ft x 5.4 ft x 3 ft to 20 ft x 7.5 ft x 6 ft, with a feed rate that has doubled to 80 lbs/hr. Cincinnati Inc. now offers a wider portfolio of 3D printers, including a Medium Area Additive Manufacturing system with a 1m x 1m x 1m build volume and 1 kg/hr deposition rate, as well as desktop-sized Small Area Additive Manufacturing printers.

The ability to handle composites with higher carbon fiber content has been achieved, as well. When 3D printing the first vehicle chassis for Local Motors, a 15 percent carbon fiber fill was used. In some cases, up to 50 percent carbon fiber content has been printed. Cincinnati states that “dozens of materials” have been used on its BAAM machines, such as ABS, PPS, PC, PLA, and PEI. In addition to carbon fiber, glass fiber and organic fiber have been used for reinforcement.

Taking a cue from its competitor, CNC manufacturer Thermwood developed its own large-scale additive extrusion technology, the Large Scale Additive Manufacturing (LSAM) series. Available with either a fixed or moving print table, the dual-gantry LSAM series is available with a print volume of 10 ft x 20 ft x 10 ft or 10 ft x 40 ft x 10 ft and can deposit 500 pounds of material per hour. And, while projects made by the BAAM printer require post-processing via CNC milling, the LSAM series has built-in machining capabilities that bring near-net-shape blanks to their final form.

Ingersoll’s MasterPrint was used to 3D print this boat. Image courtesy of Ingersoll.

To beat out everyone else in the manufacturing equipment space, Ingersoll Machine Tools worked with ORNL to develop the MasterPrint 3D printer, capable of 3D printing objects as large as 100 feet long, 20 feet wide and 10 feet tall at rates of 150 lbs/h to 1000 lbs/h. The system also features a CNC tool for machining parts to completion. We should note here that Thermwood claims its LSAM platform can be extended to be 100 feet long, though we have not yet seen such a setup.

Ingersoll sold its first MasterPrint system to the University of Maine, which it used to 3D print a 25-foot, 5,000-pound boat in under 72 hours. The ship, which will be used in a simulation program, had the distinction of achieving a Guinness World Record for the world’s largest solid 3D-printed item and largest 3D-printed boat.

The goal of the printer for Ingersoll is to fabricate massive tools for the aerospace industry. Upon the unveiling of the massive ship, CEO Chip Storie said, “The reality is we went into this technology targeting aerospace and you can print a large aerospace tool in a matter of hours or days where if you go the traditional route, it can take nine or 10 months to be able to build a tool. The cost difference for traditional tooling can run upwards of a million dollars to build an aerospace tool, where you can print a tool using our technology for tens of thousands of dollars. So, there’s a huge cost benefit. There’s a huge time benefit for the aerospace industry.”

The composites being used by these companies may only feature chopped reinforcement materials, but the speed and scale at which they can print is certainly impressive. In the case of Ingersoll, the company is working on incorporating hybrid modules that include fiber placement, tape laying, inspection and trimming.

We may see such systems as these become commonplace in certain manufacturing environments, particularly if continuous reinforcement can be integrated into the process. To learn more about the future of carbon fiber 3D printing, we’ll be looking at research endeavors in this field in our next section in the series.

The post State of the Art: Carbon Fiber 3D Printing, Part Six appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Zhejiang University Sheds Light on APVC with 3D Printed Surgical Models

Researchers from China’s Zhejiang University are looking for new ways to improve preoperative planning for procedures for children, with their findings outlined in the recently published ‘Utility of three-dimensional printing in preoperative planning for children with anomalous pulmonary venous connection: a singer center experience.’ Many of the greatest benefits were put into action for this study as the 3D printed models could be used for completing diagnosis, assessing treatment options, and planning for surgery.

In this study, Chinese medical scientists studied 17 children diagnosed with anomalous pulmonary venous connection (APVC) from November 2017 to January 2019. Ages ranged from only two days old to twenty months old, with the following variations:

  • Ten children suffering from total supracardiac APVC
  • One child suffering from intracardiac APVC
  • Mixed type APVC in one child
  • Partial APVC in three children

Data from CT scans was imported into Mimics 19.0 software for 3D modeling and design of the heart model to display elements of the heart such as papillary muscles, muscle bundles, and outflow tracts. While very little research has been performed for APVC citing the assistance of 3D printing, it is clear from this study that the use of models allows for much greater light to be shed on the condition.

“We manually labelled each area according to the left ventricle (LV), right ventricle (RV), LA, RA, aorta (AO), and pulmonary artery (PA) area modules of the CT heart module and distinguished them with different colors. Special attention was paid to labeling the boundaries of each part,” stated the researchers.

Image segmentation and postprocessing in Mimics 19.0 software. The colored masks were segmented for 3D modeling. (A) Coronal plane; (B) transverse plane; (C) Sagittal plane; (D) 3D modeling. Green, superior vena cava and right atrium; purplish red, pulmonary veins and left atrium; purple, right ventricle; orange, left ventricle; red, aorta; dark blue, pulmonary artery.

Four cases diagnosed with supracardiac type TAPVC. (A) Refers to patient 1, view from posterior; (B) refers to patient 5, view from posterior; (C) refers to patient 9, view from posterior; (D) refers to patient 10, view from posterior. *, obstruction exists at the junction of the common pulmonary venous confluence to the left-sided vertical vein (VV). Ao, aorta; PA, pulmonary artery; PV, pulmonary vein; SVC, superior vena cava. Orientation labels: I, inferior; L, left; R, right; S, superior.

Two cases diagnosed with intracardiac type TAPVC. Part of the hollowed heart model was segmented to emphasize the PV and RA we focused on. Pulmonary vein through the coronary sinus opening in the right atrium. (A) Refers to patient 11, view from inferior; (B) refers to patient 12, view from the right. CS, coronary sinus; IVC, inferior vena cava; PV, pulmonary veins; RA, right atrium. Orientation labels: A, anterior; I, inferior; L, left; P, posterior; R, right; S, superior.

One case (patient 13) diagnosed with infracardiac type TAPVC, view from posterior. The red arrow indicates the junction of the pulmonary vein and the inferior vena cava. Ao, aorta; IVC, inferior vena cava; PV, pulmonary vein; VV, vertical vein; TAPVC, total anomalous pulmonary venous connection. Orientation labels: I, inferior; L, left; R, right; S, superior.

Three cases diagnosed with PAPVC. Images (A,B) both represent patient 15. (A) The blue arrow points to RPV flowing into the right atrium. View from posterior. (B) The blue arrow represents the outlet of RPV, flowing into the right atrium. View from the right. (C) Patient 16 diagnosed with PAPVC; the blue arrow represents RPV flowing into the right atrium. View from posterior. (D) Patient 17. The blue arrow represents RSPV flowing into the SVC. View from posterior. Ao, aorta; CoA, coarctation of aorta; IVC, inferior vena cava; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; RA, right atrium; RIPV, right inferior pulmonary vein; RPV, right pulmonary vein; RSPV, right superior pulmonary vein; SVC, superior vena cava. Orientation labels: A, anterior; I, inferior; L, left; P, posterior; R, right; S, superior.

Two cases underwent cardiac CT examination during follow-up. (A,D) Blood volume; (B,C) hollowed models. Images (A,B,C) represent patient 3 after repaired supracardiac TAPVC. (A,B) view from posterior; (C) view from anterior. (C) The blue and yellow arrows represent the opening of the right pulmonary vein and left pulmonary vein. There is no anastomotic stenosis. (D) Superior view of patient 4 after repaired supracardiac TAPVC. Stenosis of LSPV (blue arrow) is shown compared to other pulmonary vein branches. Ao, aorta; LA, left atrium; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; PA, pulmonary artery; PV, pulmonary vein; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein. Orientation labels: A, anterior; I, inferior; L, left; P, posterior; R, right; S, superior.

3D printing of the personalized heart models was completed via an ISLA 650 3D printer (Shining 3D, China). Preoperative planning was then based on the models, along with medical history of the patients, and imaging data. The models were also used as surgical guides in the operating room upon being sterilized. Each patient-specific heart model took around half an hour to two hours to model, with 3D printing requiring anywhere from two to five hours. Surgeries were performed on all 17 patients, and each procedure was successful.

“The malformations demonstrated by the 3D models were consistent with intraoperative observations, and presurgical planning was in line with real surgery programs. These heart models could be sterilized and brought into the operating room for surgery navigation. These 3D models greatly assisted the presurgical planning for APVC surgery and were of great clinical value from our experience.”

“After surgeries, these heart models were evaluated on whether they were of high quality, and whether they could help presurgical planning, reduce unforeseen circumstances, and benefit medical education. An evaluation pertaining to the issues above was conducted via questionnaire by our cardiac surgeons and cardiologists.”

3D printed heart models and medical devices such as implants have been used in connection with cardiac issues and defects, with guides and models used in everything from complex medical training to pediatric surgeries, methods for creating heart patches, and more.

What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘Utility of three-dimensional printing in preoperative planning for children with anomalous pulmonary venous connection: a singer center experience’]

The post Zhejiang University Sheds Light on APVC with 3D Printed Surgical Models appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

State of the Art: Carbon Fiber 3D Printing, Part Five

In the first part of our series on carbon fiber 3D printing, we discussed how the material is used in the larger world of manufacturing. As we’ve learned throughout this series, carbon fiber (along with other reinforcement materials) is typically used as a low-cost alternative to metal, given its high strength-to-weight ratio. Though the material is found most frequently in the aerospace industry, it is increasingly used in other sectors, such as automotive, sports and construction.

What’s we’ve focused on a bit less in this report so far is how it has been and will be used in 3D printing.

The Benefits of 3D Printing + Carbon Fiber

All of the additive technologies we’ve explored have their unique benefits and drawbacks, with some processes more limited in geometric complexity and others unable to deliver the same strength and stiffness as the rest. However, the advantage that they all have in common is a high degree of automation.

Traditionally, applying carbon fiber reinforcement is a manual and time-consuming process, which can be expensive in terms of labor hours. When it’s performed using industrial automation technology, as found in large aerospace facilities, it is extremely expensive. The highest of high-end automated fiber placement (AFP) machines can cost millions of dollars.

In contrast, 3D printing is a relatively automatic process. Once a CAD model has been finalized and is appropriately set up for fabrication by a given 3D printer, the additive manufacturing (AM) system itself will do most of the work (except for post-processing, loading up materials, configuring the printer, etc.).

With some desktop continuous carbon fiber 3D printers from Markforged, Desktop Metal and Anisoprint priced between $4,000 and $20,000, small businesses and workshops can have access to an automated method for producing carbon fiber-reinforced parts. For much larger firms, emerging systems, like those from Impossible Objects and Arevo, could make batch production much possible. And in either case, the technology will likely be less expensive than AFP.


Markforged has been on the market the longest and, therefore, has the most case studies demonstrating the range of uses for continuous carbon fiber 3D printing. That has also given it plenty of time to find use cases running the gamut from prototyping and tooling to end part manufacturing.

For example, Brooks, a publicly-traded automation equipment manufacturer, uses 3D printing to prototype end effectors meant to handle fragile goods like products like semiconductor wafers. The company claimed that its previous 3D printer was not capable of printing robust prototypes, but that carbon-fiber-reinforced designs were thin enough and stiff enough for the application.

A 3D-printed lifting tool, made using Markforged carbon fiber 3D printing. Can lift 960 kg. Image courtesy of Markfoged.

Tooling is a popular application for many Markforged customers, given the strength and durability of reinforced polymer parts. These can vary, including small jigs and fixtures to “the world’s first 3D-printed CE-Certified lifting tool”.

Using the X7 3D printer, Wärtsilä 3D printed a lifting tool for moving heavy ship engine parts, such as pistons. The marine and energy firm believed its typical steel machining process to be too expensive and opted for 3D printing a polymer lifting tool reinforced with carbon fiber. The resulting part was 75 percent lighter while capable of lifting 960kg. Wärtsilä believes that it saved €100,000 in tooling alone by printing the part.

In another case, a Canadian energy services company used Kevlar, high-strength, high-temperature fiberglass, and carbon fiber to reinforce tooling on its manufacturing equipment. Using Markforged’s lowest-cost option, the Mark Two, the firm printed 53 different parts for its pad handling machine, such as fuse covers, motor mounts, end effector laser mounts and more. The company estimated a total of CAD$27,000 in savings.

Robotic arm 3D printed with continuous carbon fiber. Image courtesy of Markforged.

The Boston-based startup has also seen its technology deployed for production of end parts. Haddington Dynamics  is an engineering startup that uses 3D printing to manufacture parts for a 7-axis robotic arm for such customers as NASA, GoogleX and Toshiba. 3D printing allowed the company to reduce part count on the design from 800 to under 70, including custom swappable 3D printed gripper fingers. To produce parts that are more robust, Haddington reinforces a chopped carbon fiber-filled nylon with continuous carbon fiber.

Though still newer to the market, Arevo has also been making a name for itself in mass production. The Silicon Valley firm is partnering with Franco Bicycles to 3D print continuous carbon fiber single-piece unibody frames for a new line of e-Bikes.

Arevo will be 3D printing a unibody bike frame for Franco Bicycles. Image courtesy of Arevo.

Fortify has devoted an entire business line to a very interesting application for its magnetic approach to composites. The startup has a service for the additive fabrication of tooling for the injection molding industry, though Fortify is relying on a proprietary ceramic material for this application. The material is durable enough that mold could last hundreds to thousands of shots, according to the company. Yet, unlike traditional molds, these parts are delivered in just three days and can be much more geometrically complex.

Other firms are a bit too young to go public with how their early customers are using their technologies, but demonstrator parts have been showcased. Desktop Metal, for instance, displays a variety of tooling, jigs and fixtures on its Fiber-dedicated page. Anisoprint has just three case studies up, but one is a research project that demonstrates the firm’s unique approach to reinforcing only the areas of a part that require added strength, reducing the weight of the part even further than traditional composites or other carbon fiber 3D printing approaches have executed.

As the technology begins to make its way into the marketplace, we will definitely see more applications of carbon fiber 3D printing. One area where it should continue to have a big impact is through the production of tooling and, a bit further along in the technology’s development, end parts. In the next part in our series, we’ll take a look at large-scale carbon fiber 3D printing. 

The post State of the Art: Carbon Fiber 3D Printing, Part Five appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.