A newly developed material from a team of engineers at the University of Colorado can transform into complex, pre-programmed shapes using light and temperature. The controllable, shape-shifting material, described in the journal Science Advances, could have applications in manufacturing, robotics, and biomedical devices.
Previous attempts have relied upon a collection of physical mechanisms to alter an object's texture or dimensions with programmable stimuli. However, such materials have been limited in size or extent, and the object state changes have proven difficult to reverse. The new material achieves readily programmable two-way transformations on a macroscopic level by using liquid crystal elastomers (LCEs) - the same technology used for televisions. The unique molecular arrangement of LCEs makes them susceptible to dynamic change via heat and light.
To solve this, the researchers installed a light-activated trigger that can set a precise molecular alignment before introducing an object to specific light wavelengths. The trigger then remains inactive until exposed to the corresponding heat stimuli.
For example, an origami swan could remain folded at room temperature. However, when heated to 200 degrees Fahrenheit, the same swan eases back into a flat sheet of paper. Then, as it cools and returns to room temperature, it can gradually regain the pre-programmed shape of a swan. This ability to change and reform gives this material a wide range of potential applications, especially more flexible and adaptable biomedical devices.
Image Credit: University of Colorado/https://www.colorado.edu/today/2018/08/24/shape-shifting-material-can-morph-reverse-itself-using-heat-light