A group of engineers at Massachusetts Institute of Technology (MIT) have developed a way to 3D print flexible mesh for use in wearable and implantable devices. The method is unique in that they can tune the flexibility and toughness of the material to match that of soft tissue. The results of their work was recently published in the journal Advanced Functional Materials.
“One of the reasons textiles are so flexible is that the fibers are able to move relative to each other easily. We also wanted to mimic that capability in the 3-D-printed parts,” says Sebastian Pattinson lead author of the study. “There’s potential to make all sorts of devices that interface with the human body. Surgical meshes, orthoses, even cardiovascular devices like stents — you can imagine all potentially benefiting from the kinds of structures we show.”
From the MIT article: "Inspired by collagen’s molecular structure, Pattinson designed wavy patterns, which he 3-D-printed using thermoplastic polyurethane as the printing material. He then fabricated a mesh configuration to resemble stretchy yet tough, pliable fabric. The taller he designed the waves, the more the mesh could be stretched at low strain before becoming more stiff — a design principle that can help to tailor a mesh’s degree of flexibility and helped it to mimic soft tissue.
The researchers printed a long strip of the mesh and tested its support on the ankles of several healthy volunteers. For each volunteer, the team adhered a strip along the length of the outside of the ankle, in an orientation that they predicted would support the ankle if it turned inward. They then put each volunteer’s ankle into an ankle stiffness measurement robot — named, logically, Anklebot — that was developed in Hogan’s lab. The Anklebot moved their ankle in 12 different directions, and then measured the force the ankle exerted with each movement, with the mesh and without it, to understand how the mesh affected the ankle’s stiffness in different directions."
Read more about 3d printing flexible mesh for use in personalized wearable and implantable devices at MIT.