3D printing is already widely utilized in medicine during cardiac surgeries, to make orthopedic implants, and as guides to accurately put them in place. Typically, the devices that are printed are rigid, but the body is mostly made of soft tissues.
Engineers at MIT have been working on offering clinicians a way to use additive manufacturing, another name for 3D printing, to make customizable devices that are soft and flexible, but which can also provide support where needed.
The researchers are now able to print bespoke, flexible meshes made out of thermoplastic polyurethane which have characteristics similar to collagen’s microscopic-scale internal structure. Collagen’s strength and pliability derives partially from its intertwined strands, that are flexible and stretchable, but at some point begin to forcefully resist deformation when taken to their limit.
The new material has similar wavy patterns, which can be made to be tighter and closer together to create areas of greater stiffness. Throughout the material, different areas can have different physical characteristics, which can serve to stabilize a joint in one direction while giving it free reign in another.
To test the clinical applicability of their material, the MIT team created a special mesh for an ankle brace. It was made so that the foot doesn’t turn inward while giving it freedom to make safe movements normally used for walking. This can help to prevent a repeat injury to an ankle while giving patients a comfortable way to quickly recover. Another device was made to stabilize a knee, conforming to its awkward shape as it is bent during walking.
Though the current proof-of-concept devices are designed for external use, the researchers believe that because of its soft tissue-like characteristics, their material may have a great deal of potential for implants in a variety of locations in the body.
Study in journal Advanced Functional Materials: Additive Manufacturing of Biomechanically Tailored Meshes for Compliant Wearable and Implantable Devices