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(THE CONVERSATION). A new method of 3D printing silicone can create accurate models of blood vessels in the brain. This allows neurosurgeons to practice with more realistic simulations prior to operating, according to our newly published research.
Many neurosurgeons practice each surgery before they get into the operating room based on models of what they know about the patient’s brain. But the current models neurosurgeons use for training don’t mimic real blood vessels well. These models lack essential structural details and provide little tactile feedback. They also often miss important anatomical elements that will determine the procedure’s outcome. Pre-surgery simulations that simulate the brains of patients could help reduce errors in real surgery.
3D printing however could create replicas with the softness and the structural accuracy required by surgeons.
3D printing can be described as the process of layering layers of melted plastic, which solidifies when a structure that is self-supporting is constructed. Many soft materials don’t melt and re-solidify in the same way that 3D printers use plastic filament. Users only get one shot with soft materials like silicone – they have to be printed while in a liquid state and then irreversibly solidified.
3D Shaping of liquids
How can you create a 3D complex shape from liquids, without making it a puddle or a lump?
This was possible using an embedded 3D printer, which researchers have developed. With this technique, the “ink” is deposited inside a bath of a second supporting material designed to flow around the printing nozzle and trap the ink in the place right after the nozzle moves away. By holding liquids in three-dimensional space, users can create complex shapes from them until they are solidified. The embedded 3D printing process has proven to be effective in structuring soft materials such as hydrogels, microparticles, and even living cells.
Printing with silicone is still a difficult task. While liquid silicone is an oil, most support materials are water-based. High interfacial tension is a driving force behind the formation of oil droplets in water. This force causes silicone structures 3D printed to deform even when supported by a medium.
These interfacial forces cause small-diameter silicone features that are smaller than a standard to burst into droplets when they are being printed. Although silicone materials are now able to be printed without the support of a support, there has been a lot more research. However, these modifications can also alter the properties that users value, such as the softness and stretchiness of the silicone.
3D-printing silicone using AMULIT
We are researchers at the interface between soft matter physics and mechanical engineering. Therefore, we developed a silicone oil-based support material to address interfacial tension.
We figured that silicone inks would most likely be chemically identical to our silicone support material. This will dramatically reduce interfacial tension and also allow for separation when 3D printed. There were many candidates for support materials that we tested, but the best was to create a dense silicone oil-water emulsion. You can think of it as crystal clear mayonnaise. It is made of microdroplets packed with water and silicone oil. This is additive manufacturing at ultra low interfacial tension or AMULIT.
Our AMULIT support medium allowed us to print off-the shelf silicone at high resolution. We were able create features as small and as small as 8 micrometers (around 0.03 inches). The printed structures are just as durable and stretchy as traditional molded ones.
These capabilities enabled us to 3D-print accurate models of a patient’s brain blood vessels based on a 3D scan as well as a functioning heart valve model based on average human anatomy.
3D silicone printing in the health care industry
Silicone is a crucial component in many products. These include everyday items like toys and cookware to high-tech electronics and aerospace technologies.
Silicone products can be made by injecting silicone liquid into a mold, and then removing the cast from solidification. High-precision molds can be expensive and difficult to manufacture. Therefore, manufacturers are restricted to making products in a limited number of sizes, shapes and designs. Molding intricate structures requires the removal of delicate silicone structures without damage.
These issues could be overcome, which could lead to the development of advanced silicon-based technologies in health care. Personalized implants or patient-specific imitations of physiological structures could transform healthcare.
This article was republished by The Conversation under a Creative Commons licence. Read the original article here: https://theconversation.com/3d-printing-the-brains-blood-vessels-with-silicone-could-improve-and-personalize-neurosurgery-new-technique-shows-how-202226.