Parallel to the development of four-dimensional medical scanning, there has been an emerging trend of 4D printing technologies. These additive manufacturing technolo-gies allow the use of smart bioactive materials, which can adapt and change over time. Like traditional additive manufacturing methods, they use 3D printing technol-ogies to generate objects from 3D- CAD models, while adding the new dimension of time through smart materials (1). These materials change their shape or structural characteristics based on surrounding factors like humidity, tem-perature or pressure over time. There is a great need for these opportunities, espe-cially when it comes to applications like bone implants or stents, which can grow with the human body or allow ingrowth. Moreover, the creation of composite mate-rial comprised of different raw and bioactive materials can have positive effects on the stiffness, durability, flexibility and loading capacity of printed objects (2).
Nevertheless, due to the early developmental stages of the 4D manufacturing technique, there are a few limitations which need to be considered regarding overall process outcome and economic feasibility. Yet, the accuracy of these processes still needs to be improved in order to prevent discomfort in the patient. Additionally, the long-term effects of smart materials used in the human body as well as general mate-rial characteristics still need further research (3).
by medineer
(1) Kuang, X., Chen, K., Dunn, C.K., Wu, J., Li, V.C.F. and Qi, H.J. (2018) ‘3D Printing of Highly Stretchable, Shape-Memory, and Self-Healing Elastomer toward Novel 4D Printing’, ACS applied materials & interfaces, Vol. 10, No. 8, pp.7381–7388.
(2) Maniruzzaman, M. (2018) 3D and 4D Printing in Biomedical Applications. Process Engineering and Additive Manufacturing, John Wiley & Sons Incorporated, Newark [online] https://ebookcentral.proquest.com/lib/gbv/detail.action?docID=5612867.
(3) André, J.-C. (2017) From additive manufacturing to 3D/4D printing. 3: Breakthrough innovations : programmable material, 4D printing and bio-printing, ISTE; Wiley, London, UK, Hoboken