Thanks to a collaboration between the University of Pisa and the Jozef Stefan Institute in Ljubljana, the first shape memory liquid crystalline elastomer that can be reprogrammed in three dimensions has been created. The research published in the journal “Nature Communications” paves the way for many future developments related to the possibility of combining this material with a 3D printing system to create objects of any shape in a totally versatile manner.
Prior to this research, liquid crystalline elastomers, materials capable of reversibly changing their own shape when subjected to external stimuli such as temperature, electric fields, or light, were essentially prepared in the form of films. They could therefore only shorten or lengthen, with uniaxial deformation. Although variations of up to 400% of their initial shape could be achieved, the typical geometry of films limited the possible applications, which today are mainly in the field of optics, micro and soft robotics, and sensor technology in general.
"The new material we have created, allows us to obtain very varied geometries and shapes, effectively moving from a two-dimensional to a three-dimensional world”. - explains Valentina Domenici from the Department of Chemistry and Industrial Chemistry at the University of Pisa – “The novelty, moreover, is that it can be remodelled and reprogrammed each time to obtain objects with ever-changing geometries and shapes. In the future, it could be used with 3D printer technology or by exploiting the potential of microfluidics, for virtually infinite applications”.
The new class of materials created and studied over the years by the research team of Professor Domenici and the Slovenian team led by Professor Boštjan Zalar and researcher Andraž Rešetič is called “PDLCE” from “polymer-dispersed liquid crystalline elastomers”. Specifically, the research in “Nature Communications” focused on a particular type of PDLCE material that has two transition temperatures, both above room temperature.
“My role in this research”, Professor Domenici concludes, “mainly concerns the design of the chemical components and the choice of the appropriate base molecules for the preparation of liquid-crystalline elastomers, in order to obtain a final material with the best thermo-mechanical and elastic properties. I am the only chemist in this research group, all the other members of the Slovenian group are physicists. This synergy is the basis of a collaboration that has been going on for over twenty years and has enabled us to achieve many excellent results”.