Advanced Fabrication: Metal Printing

Metal 3D printing can be achieved with a range of different technologies, including Selective Laser Melting (SLM), Binder Jetting Metal printing, and Fused Deposition modelling (FDM). All the different types of metal printing use the same basic principles of 3D printing, by building a model layer by layer, until the model is finished. ANFF primarily focuses on the use of SLM printing, which allows for a wide range of materials to be printed and the flexibility to blend metals to create unique metallic composites.

SLM printing utilises high powered lasers to fully weld metallic powders to produce components up to 99.9% relative density of a pure metal. The common materials used by ANFF include Titanium (Ti64) and Stainless Steel (316L) for their biocompatible properties and ability to reach high-resolution prints for use in electrodes and bioprinting.

Metal printers we use

 

ANFF Materials node has three different metal printers located at Translational Research Initiative for Cell Engineering and Printing (TRICEP), that all utilise the SLM technology outlined above. The three machines are as follows:

  • Realizer SLM50: Highest resolution metal printer in the southern hemisphere, with a laser spot size down to 10µm allowing for extremely fine detail components to be produced (down to 75µm feature size). Due to the high resolution of the printer the build volume is reduced, however this is beneficial as it allows for experimental powders (and blends) to be used within the system.

  • Concept Laser MLabs 200R: “Production” style machine with a larger build volume (100mm cubed) allowing for larger metal parts or a greater number of parts to be produced. The laser spot size on the printer is 75µm allowing for features down to 150µm to be produced.

  • TRUMPF TruPrint 1000: An experimental style SLM machine that has a 30µm spot size allowing for small features to be able to be produced. The Printer has a variable build volume that can be installed, from a 100mm diameter to a 33mm diameter build tray, allowing for the production of parts in unique and precious metals.

Examples

 

ANFF primarily focuses around the medical and electrochemical fields, using metal 3D printing to produce components traditionally unattainable through traditional manufacturing techniques. An example of this is the Bio-Pen tips that have been developed in collaboration with Peter Choong and his team at St Vincent’s Hospital in Melbourne. The challenge was to produce a tip that would allow for the coaxial extrusion of biomaterials, allowing for cells to be transported safely and in a protected fashion into the body for cartilage regeneration. Metal 3D printing allowed for complex flow paths to be designed and produced in a biocompatible titanium in order to meet the challenge.

Advanced Fabrication: Polymers

Polymer research 

 

The ANFF materials node at UoW has the following polymer printing capabilities:

  • FDM(Fused Deposition Modelling): This node has several FDM machines including the uPrint, Markforged, Creality CRx as well as a custom built printer for use with high temperature thermoplastics. The Markforged allows composite printing which carbon fibre, Kevlar or fibreglass for mechanically superior printed components.

  • SLA(Stereolithographic Apparatus): A Formlabs Form 2 is used where a smooth surface finish is required in conjunction with good mechanical properties. White, tough and dental materials are most commonly run.

  • Inkjet: The Mimaki 3DUJ-553 is the in house full colour inkjet 3d printer with the option to have a solid white or clear base material. This printer is used to make brilliant models of scientific data which is a great asset for science communication.

  • PolyJet: For most of the biocompatible printing, the Connex 350 is used with med610 material. The Connex 350 is also capable of running flexible and solid materials with digital mixing in print. This allows for single components to have a variable shore hardness in defined regions.

Examples

The most interesting novel polymer system developed at this node is a 6 axis conformal melt electro writer (MEW). Using molten PCL as the material, a robotic arm holds a metal syringe over a metal substrate and a several thousand-volt charge is applied between them. This draws a very fine strand (5-15 microns diameter) of PCL to the substrate. The control algorithms allow this strand to be deposited in defined locations over a 3d contoured surface. The applications of such a fabrication method are in the bio sector, mainly in tissue repair

 
 

Advanced Fabrication: Fibre Spinning

The materials node also offers complete capabilities for fibre spinning and fabrication of fibrous structures at different scales. The available fibre spinning and fabrication instruments are:

  • Wet-spinning machine

  • Twin-screw extruder for melt-spinning

  • Electrospinning machine

  • Knitting machine

  • Braiding machine

  • Other available processing/fabrication instruments are

  • Probe sonicators

  • Thinky mixer

  • Centrifuges

  • Polymer grinder

  • Hotpress

 

Advanced Fabrication: Roll-to-Roll Functional Printing

 

Harnessing the power of industry standard roll-to-roll printing equipment more typically used to produce stickers and labels, ANFF materials can create multi-layer electronic devices such as solar panels and sensors. The Newcastle Hub of the Materials Node has a pilot-scale facility that includes multiple roll-to-roll (R2R) systems which can print ink layers, metal layers, and encapsulate devices.  R2R printing offers the ability to rapidly coat vast areas of material at low-cost and high-throughput, which allows for rapid scaling from research and development stage through to production.

R2R tools and processes available at the Newcastle Hub

 

  • Coating line: The Solar 1 coating line from GM is a reel-to-reel (R2R) coating system which can take a range of webs (substrates) and deposit inks using various coating techniques such as Gravure, Flexographic, rotary screen-printing and slot-die coating. The Solar 1 line is designed for 300 mm wide web and has two 1m ovens for drying. This versatile system allows for a range of conductive and non-conductive inks to be deposited.

  • Sputter coater: The R2R sputter coater is a 3-target system that can coat rolls up to 100 m in length (300 mm wide) in various metals including aluminium, silver, and titanium. These depositions can also be patterned when required for electrodes and separate devices.

  • Laminator: The R2R laminator is used to encapsulate materials in barrier film plastics. It utilises a flexographic station to deposit UV curable glues which are then cured in-line using a 5kW UV lamp. This system can also be used to apply other layers such as conductive tapes and separating films.

  • Ink preparation: All of the processes in the print facility begin with the ink formulation. The Newcastle Hub has facilities to synthesise and prepare many polymer-based inks and polymer nanoparticle inks.

  • Bench coaters: Batch scale testing of printing processes is carried out using the bench coating systems available in the Hub including flatbed screen printing and single stripe slot-die coating. A Fujifilm Dimatix Materials printer is also available allowing for precise 2D patterning of functional inks for sensors and other electronic devices.

Examples

Flexible printed solar panels made from polymer materials are a next-generation energy technology being developed at the Newcastle Hub. Targeting low-cost power from materials that are fully recyclable, this project is taking advantage of the ability for R2R processes to produce consistent, uniform layers over kilometres. Utilising the complete suite of tools at the pilot-scale facility, the produced solar panels are being deployed to sites like ‘The Canopy’, a public multi-use space in Lane Cove which has the only public display of this technology anywhere in Australia.

iQX Ltd is developing a saliva- based blood glucose monitoring strip. These sensors can simply be licked to provide a saliva sample for glucose monitoring by diabetics, significantly increasing their quality of life. Based on a printable transistor platform, these devices have been developed for many years at laboratory scale using typical lab processes. Now these exciting developments are being translated onto R2R printing equipment, greatly increasing the volume of sensors able to be produced and demonstrating their production using techniques that are very close to the commercial production process.

 
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Materials Supply

Advanced Fabrication

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