Shape-memory Photoresins

Shape-memory photoresins are a subcategory of shape-memory polymers. They are mixtures of suitable monomers, oligomers and special additives. These materials are able to perform on compatible 3D printers. They have a permanent shape and can attain an infinite number of transition shapes when exposed to specific stimuli and force. When the stimuli are removed, they are frozen in their transition shape and keep the shape for a very long time. Again, as soon as the stimuli is applied to the transition shape, it changes simultaneously and tries to attain the permanent shape. This is called Shape Recovery. The extent of shape recovery depends on different factors such as the intensity of the stimulus, time of recovery, inherent thermodynamic and kinetic characteristics of the material and also the design of the part and the neighboring parts and elements. 

One of the stimuli, which is important from the application point of view, is Heat. Heat can be used to induce transitions in the shape of a part printed using shape memory photoresins. Heat is very easy and quick to generate, and therefore it can be used to quickly force the object to response. Temperature-responsive 4D printing photoresins can be used to make parts of different response rates to heat and force. They can be designed to show a wide variety of modulus-temperature and modulus-time variations. In other words, they may be easy or hard to deform or either quick or slow to react. This depends on their inter- and intramolecular forces and the details of their molecular structure. 

Shape-memory photoresins can be used in applications such as sensors, electronics, soft robotics, artificial muscles, origami and deployable structures, metamaterials and ultra-strong structures and many other fields of the future technology. 

While it is not possible to find a wide variety of shape-memory photoresins in the market nowadays, these materials can be expected to form an important part of future global 3D printing market.