4D printing applications in medical field: A brief review

Background/objectives There are promising applications of 4D printing in the medical field. The need is to identify the research status and explore where this new set of technologies effectively can be deployed. Methods Research articles till September 2018 are searched from Scopus by keywords as "4D printing" and "4D printing""medical" and undertaken a bibliometric analysis of the identified papers. Further relevant papers were studied for application in the medical field. Results Search through Scopus identified 171 research articles on 4D printing and 13 research articles on 4D printing in the medical field. This study states that 4D printing is the latest technology that creates innovation and addresses complex medical problems. Paper briefly describes the 4D printing and details its difference from 3D printing technology. We have identified five steps to be used to create a medical model by using this technology and its prospective implementation for medical applications. Identified that research is carried out on 4D printing, but decidedly less publication is available in the medical field reporting the application of this technology. Finally, we have identified nine significant applications of 4D printing in the medical field. The main limitation is that it requires extensive investment & support for transformation. Conclusions 4D printing is to provide benefits to medical practitioners especially in the areas not covered by 3D printing technologies. 4D printing helps to create a 3D physical object by adding smart material layer by layer through computer-operated computer-aided design (CAD) data. It adds a dimension of transformation over time where printed products are sensitive to parameters like temperature, humidity, time etc. This technology can provide extensive support in the medical field, especially with better and smart medical implants, tools and devices. Now doctors and researchers can explore with 4D printing technology to provide better service to the patient.