One of the challenges of making 4D printed smart objects available to the general public, or even making it affordable for private businesses, is the fact that it may be more costly than its worth. Today 4D objects are in its earliest days of research, 3D printing is still catching on and it hasn’t even evolved to its fullest potential. Before we even see the democratization of smart objects into the market we have to see it develop and evolve. Luckily there is already plenty of enthusiasm in the scientific community about this type of technology and many engineers and researchers are already working on improving on current models.
The simplest way to explain 4D printing, is to explain the fourth dimension, which is time. 4D printing will utilize 3D printed components, but these components will be capable of evolving, transforming their structure both on the macro and micro level over time. Currently the 4D objects that have been produced use shape memory polymer fibers which can be arranged in a way that gives the object unique abilities. for example, if arranged in a specific way a 4D printed object will be able to fold, curl, stretch and twist. Researchers have also worked on smart objects which respond to more basic changes in the environment: changes that are triggered with varying temperature, pressure, or substance, for example by water.
Currently the biggest investor in this technology is the US Army Research office. They have already invested 855,000 dollars to several research teams working on developing 4D printing. Some of the ideas they have been working on are adaptable camouflage uniforms for soldiers, adaptable gear, and self healing, and self assembling technology.