Special Issue - 4D Printing: Call for Paper

From the Guest Editor, Prof. Giovanni Vozzi:

Four dimensional (4D) printing was first introduced in 2013 and immediately had great attention in various research areas such as smart materials and biomedical research. A 4D structure is a 3D printed object which can, immediately after printing, self-transform in form or function when exposed to a predetermined stimulus, such as osmotic pressure, heat, current, ultraviolet light, or other energy sources. The change in shape is mainly due to two factors: 1) presence of a “smart” materials that can respond to the stimulus or stimuli; 2) well defined topological structure, where the “smart” materials are located in the volume of the object, so that their local interactions can generate predefined movements.

Although the surrounding environments may change significantly during the 4D process, the configuration or function before and after the stimulation should be structurally or functionally stable. This feature is a controversial point of discussion because all 3D printed constructs made of biodegradable materials change their structures when interact with physiological environment, so they could defined 4D printed structures, but they are not able to recover their initial shape due to biodegradation. In this issue, it is important to consider also 4D printed biological support structures that are biocompatible topologically defined structures able to change their shape under a well defined stimulus or stimuli combination and in this way are able to recover or restore a damaged fucntion of a physiological tissue, reconstructing its natural activity.

This special issue we will focus on the latest advances in: 1) novel materials or their combination to fabricate 4D printed structures; 2) innovative design of 4D printed structures; 3) novel strategies of 4D printing technologies; 4) realisation and characterisation of 4D printed prototypes.