Cambridge, Massachusetts – Engineers at the Massachusetts Institute of Technology have designed pliable 3D-printed mesh materials for medical applications such as knee and ankle braces. The flexibility and toughness can be tuned to emulate and support softer tissues such as muscles and tendons.
The design of the wavy-patterned flexible meshes was inspired by the pliable nature of fabrics, and the natural structural protein collagen, which resembles curvy, intertwined strands under the microscope. These were printed using thermoplastic polyurethane. The taller the waves, the more the mesh can be stretched at low strain before becoming more stiff.
The intricate structures in each mesh can be tailored to make tough, stretchy fabric-like material for personalised, wearable supports. They might even be applicable to implantable devices such as hernia meshes.
To demonstrate the concept, the team printed a flexible mesh for use in an ankle brace. Its structure was tailored to prevent it from turning inwards, while allowing the joint to move freely in other directions.
Other test devices they have made include a knee brace that could conform to the knee as it bends, and a glove with mesh sewn into the top service that conforms to the knuckles, providing resistance against the involuntary clenching that can occur after a stroke.
‘3D-printed clothing and devices tend to be very bulky,’ said study leader Sebastian Pattinson. ‘We were trying to think of how we can make 3D-printed constructs more flexible and comfortable, like textiles and fabrics.’
The study has been published in the journal Advanced Functional Materials.