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London: 3D Printing the Double-Ridged Horn Antenna for Biomedical Monitoring

Researchers are looking into ways to optimize biomedical monitoring, with their results outlined in ‘A 3D Printed High-Dielectric Filled Elliptical Double-Ridged Horn Antenna for Biomedical Monitoring Applications.’ Seeking to make further impacts in the field of medical science, the team from Queen Mary University of London has 3D printed an innovative device for sensing applications with wireless technology—based on ultra-wideband devices initially created for short-range wireless communications.

The in-house measurement setup based on the open-ended coaxial probe technique, used for the characterization of the dielectric materials.

Created to work within UK Communications Industries (Ofcom) and the Federal Communications Commission (FCC) regulation of UWBs, the new device has been found to offer depth suitable for penetration in scanning skin, muscle, and fat, with signals able to sense layer thicknesses. Wide-band technologies are often used for short-range communication due to:

  • Low power
  • High data rates
  • Multipath immunity
  • Simultaneous ranging and communication

While this type of antenna is not new, the use of 3D printing is novel. The double-ridged horn has been a topic of research over the years for researchers because of the benefits, leading to a more effective answer to refining accuracy in biomedical scanning. And while 3D printing can offer greater affordability in many cases, here the research team was concerned about cost-prohibitive fabrication, so they compared materials, ultimately settling on in-house 3D printing with ABS.

The shape of the horn allows for better operation overall, and the high dielectric material allows for a miniaturized design that also reduces reflection and is both easy and affordable to make. With an extension, the scientists were able to expand on the antenna and prevent signal-overlapping issues.

Modeled extended EDRH antenna with the structural labels and the dimensions for the extended section.

“The optimal approach is to extend the outer aperture of the antenna, and to define, the antenna outer aperture length, so the scanning tissue area can be placed in the far-field region,” stated the researchers. “This has added more complexity to the fabrication and realization of the device with the increased cost, but on the other hand, it has made it more stable in its operation, and free of any destructive interference signals and noise.”

The team used the Stratasys Objet30 Prime 3D printer for creating their prototype, finishing it with clear Vero polyethylene, stating that hardware and materials not only offered high resolution, accuracy, and conductivity, but also affordability in fabrication.

Measurements were found to be accurate also, as they addressed concerns regarding individual and other influences like scanning areas and layer structure but concluded that there should be very little variance between ‘permittivity and thickness.’ If an impact on the results was noted, the researchers explained that added calibration measures could be taken with an open-ended probe, with software producing the results.

(a) 3D-printed EDRH antenna using the polyethylene material. (b) 3D-printed EDRH antenna, as conductive-painted and fed with a semi-ridged SMA connector. (c) 3D-printed EDRH antenna filled with the high-dielectric mixture.

“This design incorporates the extension for locating the antenna in the far-field region of the scanning area, for the plane-waves to penetrate more directly into the body. Moreover, the antenna can operate at the lower frequency band of WB to exhibit a better penetration depth and impedance matching using the mixture for the biomedical application, which monitoring very deep inside the body is the main objective of the system,” concluded the researchers at the end of their study.

3D printing has offered much greater expansion opportunities for scientists and engineers interested in creating better devices for sensing and monitoring, from automotive sensors to electrochemical sensing, and 3D printed models for better monitoring.

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: ‘A 3D Printed High-Dielectric Filled Elliptical Double-Ridged Horn Antenna for Biomedical Monitoring Applications’]

 

The post London: 3D Printing the Double-Ridged Horn Antenna for Biomedical Monitoring appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

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Bioprinting 101: Part 3 Industrial Printers

Today we will look into bioprinters that are well known. One must understand biochemistry, and other important aspects within biology to fully do well with bioprinting. The development of bioprinting technology will take patience and time. The climb will be steep but in the future, and it may very well have huge impacts on the future of health for society.

There are 4 typical printing setups that can be associated with bioprinters. These include:

  • Extrusion
  • Inkjet
  • LIFT
  • Stereolithography

Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed through a die of the desired cross-section. The two main advantages of this process over other manufacturing processes are its ability to create very complex cross-sections, and to work materials that are brittle, because the material only encounters compressive and shear stresses. It also forms parts with an excellent surface finish. Syringe nozzles are often used for extrusion purposes in 3D bioprinters.

Inkjet printing uses a printer head that moves across a variety of substrates, selectively depositing a liquid binding material. A thin layer of material is spread across the completed section and the process is repeated with each layer adhering to the last. When the model is complete, unbound material is automatically and/or manually removed in a process called “de-powdering” and may be reused to some extent.

LIFT printing refers to laser-induced forward transfer. LIFT is a relatively new printing technique that enables transfer from a thin-film donor material onto your chosen receiver placed nearby. Unlike conventional laser-printers, which print liquids or inks, LIFT printing can transfer solid phase materials in (ideally) an intact state, for a range of applications.

Stereolithography is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photopolymerization.

Lift 3D printing

These techniques for printing are standard within the 3D printing industry. A problem within the bioprinting industry is the vast amounts of ways to conduct bioprinting. The field is still new, so there are various techniques relying on classic additive manufacturing techniques, as well as newer technology made specifically for bioprinting. The following is a list (not exhaustive) of manufacturers and the 3D bioprinters they have made:

  • 3D Bioplotter – EnvisionTec
  • Bioscaffolder – Gesim
  • Inkredible+ – Cellink
  • Biofactory – RegenHu
  • Revolution – Ourobotics
  • Bio3D Explorers –  Bio3D technologies
  • CellJet Cell Printer – Digilab
  • BioAssemblyBot, advanced solutions
  • Regenova – Cyfuse
  • NovoGen MMX – Organovo
  • Dimatrix Materials Printer – Fujifilm
  • Poietis
  • Nyscript
  • Aether
  • Allevi
  • Fabian

organovo 3d bioprinter

Organovo 3D Bioprinter

The 3D-Bioplotter System by Envisiontec is a versatile rapid prototyping tool for processing a great variety of biomaterials for computer-aided tissue engineering (CATE), from 3D CAD models and patient CT data to the physical 3D scaffold. This printer costs between $80,000 and $150,000

The Bioscaffolder manages a wide range of very different tools and ensures automatic XYZ alignment for all. The BioScaffolder also has software which allows for the definition of an inner “scaffold-”.  As with the built-in scaffold generator, up to three different materials and different pore sizes can be assigned to the CAD model.

The Allevi allows researchers to create 3D printed tissue reliably with the curing mechanism, as well as a heated dual extruder that is able to keep cells at what would normally be natural body temperature. Thermoplastic supports can be cured also during the process allowing for greater latitude in creation as well as flexibility in material being used. Users are able to put several materials into the same sample which allows for speed, diversity, and complexity.

The Inkredible 3D Bioprinter is an extrusion-based 3D Bioprinter with dual extruder heads for bioprinting of human tissue models and organs. Once the structure has been printed, it can be cross-linked using the Blue LED UV crosslinker or ionic solutions, depending on your bioink material.

The BioFactory allows researchers to pattern cells, biomolecules and a range of soft and rigid materials to create realistic biomimetic tissue models, while the 3DDiscovery system is a more cost-effective alternative designed to explore the potential of 3D engineering.

The Revolution features a hand-like retooling system. This allows for users to interact with materials that may be sensitive to human touch and interference. The system is modular, and can work with a wide variety of bioinks, regular and specialized materials. It can print with 10 materials or more at a time and it uses a heated enclosure for keeping cells alive.

Bio3D Technologies created a bioprinter with multiple print heads, modular design, nozzle-to-platform auto-alignment, remote viewing and control.This printer has integrated an anti-vibration levitating platform into a 3D printer. With the introduction of Bio3D Explorer, they made 3D bioprinting even more affordable and accessible.

CellJet holds up to 16 independent channels (i.e. many different cell types can be printed at once). More than 20 types of primary cells and cell lines have been successfully printed by a CellJet. CellJet is a compact system fitting in most of the hoods and biological safety cabinets. CellJet may come in different settings to fit the customer’s needs and be customized on demand.

The BioAssemblyBot robot arm gives you the freedom to 3D print advanced tissue structures and constructs as well as print contour. BioAssemblyBot maintains temperature control from 5 Celsius to 110 Celsius and can be adjusted during specific points in the 3D printing workflow.

The the Regenova bioprinter uses the “Kenzan” method, in which cellular spheroids are cultured in fine needle arrays. As each spheroid is placed in a particular order, they can autonomously connect and form macroscopic tissue structures without the use of collagen or hydrogel. The researchers add a series of needles to the needle array to change the length and/or thickness of their intended output.  Depending on the arrangement of the needle array, it is able to ensure circulation of the culture medium and oxygen until it is mature enough to be used.

Kenzan Method

The NovoGen MMX 3D printer, which is not for sale commercially, creates tissues that are sold to drug manufacturers. It also uses syringe-based extrusion technology, with two robotically-controlled precision print heads (one for the human cells, the other for the life-sustaining microgels) that can produce thick tissues of 20 or more cell layers.

FUJIFILM Dimatix has leveraged its piezoelectric inkjet technology and MEMS fabrication processes with its extensive inkjet product. The DMP-2850 allows the deposition of fluidic materials on an 8×11 inch or A4 substrate, utilizing a disposable piezo inkjet cartridge. This printer can create patterns over an area of about 200 x 300 mm and handle substrates up to 25 mm thick with an adjustable Z height.

Poietis is a biotechnology company specializing in the laser-assisted bioprinting of living tissue.It provides industrial stakeholders and researchers with a unique platform to design and manufacture bio-printed products for regenerative medicine, preclinical research and evaluating the efficacy of cosmetic products and ingredients.

The nScrypt has a setup consisting of Linear Motors. The XY plane of the system can travel in a range of 300 – 1500 mm. The system has a 10 nm resolution as well as 1 micron accuracy. The printer can also travel 150 – 200 mm in the Z plane. There are options for multiple printer heads in a setup.

The Aether features 8 pneumatic syringe extruders with a vertical retraction system. It also has an anodized aluminum heated syringe mount with a 30cc glass syringe. It also contains a solenoid microvalve droplet jetting extruders coupled with a 445nm Laser.

The Fabion is a 5 nozzle bioprinting system. These nozzles are programmable in terms of how they dispense materials. The main differentiator from other products is their specific biopaper material used for printing. The technology combines a variety of biofabrication methods. These include self assembly, as well as robotic control systems.

With all of these incredible 3D bioprinter technologies comes a con: A majority of these products are industry grade quality and have high price tags. If one has $10,000 or $100,000 lying around to buy said devices, great. If not, well welcome to most realities. So what are alternatives to individuals who want to know more about this particular biotech. In future articles, I will discuss the feasibility of DIY bioprinting options and how to work on making your own bioprinter.