Lu Rahman, group editor for Med-Tech Innovation’s sister title, Medical Plastics News, looks at some of the latest developments in the 3D printing sector and how origami has become a surprising new inspiration.
3D printing has been part of the medtech sector for years. Stories on the process highlight its importance and the benefits it can bring to healthcare and the general population.
The medical plastics sector hears about the cutting edge of the 3D industry on a regular basis but it’s great when the wider public gets to hear of the progress being made in the field
The Guardian highlighted the way in which 3D printing has the potential to ‘revolutionise the medical profession’ and how scanning techniques are helping the customisable artificial limbs. Amy Fallon describes how a trial by NIA Technolgies provides mobility devices for children and young people “more quickly than the conventionally produced plaster cast method – using a 3D printer and other 3D technology”.
Matt Ratto, Nia’s chief science officer told the newspaper: “Our project leap frogs current developed world fabrication techniques by using 3D printing to produce devices that are actually being used by patients”.
The trial involves the production of two different types of mobility device using scanning, modelling and printing technologies.
Self-folding medical implants
Innovation continues in the medical sector for 3D printing. Researchers at TU Delft have made flat surfaces that are 3D printed and then ‘taught’ how to self-fold later. The materials are potentially very well suited for all kinds of medical implants.
Complete regeneration of functional tissues is the holy grail of tissue engineering and could revolutionise treatment of many diseases. Effective tissue regeneration often calls for multifunctional biomaterials. A lot of research is currently going in that field. One example is the large research project, led by Maastricht UMC and with TU Delft as one of the participants, in the field of ‘smart’ 3D printed implants for recovery of bone defects. The project started this month and if it’s successful, will lead to faster recovery of patients and less operations.
But the potential applications of 3D printed bio-implants is much bigger than only bone defects. Dr Amir Zadpoor is one of the researchers at TU Delft.
“Ideally, biomaterials should be optimised not only in terms of their 3D structure but also in terms of their surface nano-patterns,” he said.
“3D printing enables us to create very complex 3D structures, but the access to the surface is very limited during the 3D printing process. Nanolithography techniques enable generation of very complex surface nano-patterns but generally only on flat surfaces. There was no way of combining arbitrarily complex 3D structures with arbitrarily complex surface nano-patterns.”
Zadpoor looks to the Japanese art of origami to solve this deadlock. Flat surfaces are 3D printed in a way to teach them how to self-fold. The surface is then decorated with complex nano-patterns. Finally, the self-folding mechanism is activated (for instance by a change in temperature) to enable folding of the flat sheet and the formation of complex 3D structures.
Zadpoor: “Nature uses various activation mechanisms to program complex transformations in the shape and functionality of living organisms. Inspired by such natural events, our team developed initially flat (two-dimensional) programmable materials that when triggered by a stimulus such as temperature, could self-transform their shape into a complex three-dimensional geometry.”
Shape memory polymer (SMP) and hyperelastic polymers program four basic modes of shape-shifting. Some of the modes of shape-shifting were then integrated into other two-dimensional constructs to obtain self-twisting DNA-inspired structures, programmed pattern development in cellular solids, self-folding origami, and self-organising fibres.
“This work is just one little step towards better medical implants’, said Zadpoor, “but we are definitely making exciting progress.”
Earlier this year Stratasys outlined what it called a ‘major advance in surgical pre-planning’ led by 3D printed anatomical models. The company teamed up with the Jacobs Institute physicians at Kaleida Health’s Gates Vascular Institute and biomedical engineers at the University at Buffalo for the design of a new approach to repair a complex brain aneurysm. The result? A life-like 3D printed replica that reduces risks associated with this complex surgery and corrected a near-fatal condition.
Dr Adnan Siddiqui, chief medical officer at The Jacobs Institute described how they took an image of the aneurysm based on scans to generate an exact replica of the entire brain vessel anatomy and how the Stratasys 3D printed model enabled the creation of a better way to treat the patient.
Stratasys technology has also been used by the Kobe University Hospital in Japan which is using model replicas of patient’s organs as educational tools and at the University of Minnesota Medical School, where a US Army-funded study is developing anatomically accurate airway trainers to improve training for medical emergencies.