text: University of Nottingham researchers have discovered a new 3D printing process to tailor-make artificial body parts and other medical devices with built-in functionality which provides better shape and durability while cutting risks of bacterial infection at the same time.
  Researchers have been able to use a computer-aided, multi-material 3D print technique, to show it’s possible to combine complex functions within one customized healthcare device to enhance wellbeing.
  The hope is to allow innovative design processes applied to 3D print medical devices that require customizable shapes and functions. For example, the method can be adapted to develop a high quality one-piece prosthetic joint or limb to replace a lost leg or finger to fit the patient perfectly to enhance their comfort and prosthetic durability; or print customized pills that contain multiple drugs regarded ad polypills enhanced to release into the body in a therapeutic sequence.
  Meanwhile, the aging population is increasing in the world, leading to a higher demand for medical devices in the future. Using this technique could improve the health and wellbeing of older people and ease the financial burden on the government.
  How it works
  Researchers applied computer algorithms to design and create pixel by pixel 3D printed objects made up of two polymer materials of different stiffness which also prevents the development of bacterial biofilm. They achieve custom size and shapes by optimizing the stiffness to offer the required strength and flexibility.
  The artificial joint replacement in use for instance the use of both metal parts and silicone that provides the wearer a standardized level of dexterity while still being rigid enough to implant into the bone. Researchers demonstrated this study by 3D printing a finger joint providing the dual requirements in one device and able to customize its length and size to meet individual patient requirements.
  The team performed new 3D style printing with multi-materials that are intrinsically bacteria resistant and biofunctional enables them to be implanted and fight infection (that occurs during and after surgery) without using antibiotic drugs.
  The team also used a new high-resolution characterization technique (3D orbitSIMS) to 3D-map the chemistry of the print structures and to test the bonding between them throughout the part. This identified that – at very small scales – the two materials were intermingling at their interfaces; a sign of good bonding which means a better device is less likely to break.
  The study was funded by the Engineering and Physical Science Research Council and carried out by the Center for Additive Manufacturing (CfAM). The complete finding is published in Advanced Science in a paper entitled: ‘Exploiting generative design for 3D printing of bacterial biofilm resistant composite devices’.
  Before the commercialization of the technique, the researchers plan to broaden the potential of uses by testing it on more advanced materials with extra functionalities such as promoting stem cell attachment and controlling immune responses.