Rotational movement in nature is very rare, while at the same time ubiquitous in our civilization. While we can build a variety of rotary motors, they usually consist of many elements and it makes their miniaturization difficult. However, there is a group of materials that enable construction of small, moving and/or mobile devices: liquid crystal elastomers (LCEs). Research on these materials focuses mainly on design of LCE shape and its change upon laser illumination (such as shrinking, bending).
These LCEs are smart materials that can exhibit macroscopic, fast, reversible shape change under different stimuli, including illumination with visible light. They can be fabricated in various forms in the micro- and millimeter scales and, by the molecular orientation engineering, they can perform complex modes of actuation.
Researchers from the University of Warsaw with colleagues from the Department of Mathematical Sciences at Xi’an Jiaotong-Liverpool University in Suzhou, China, Institute of Applied Physics at Military University of Technology in Warsaw, and Centre of Polymer and Carbon Materials of Polish Academy of Science in Zabrze, Poland, have now developed a micromotor that rotates thanks to the traveling deformation of the soft material, caused by the laser beam and its interaction with the ground. The main part--the rotor--is a 5 mm ring. Appropriate design of the orientation of the elastomer molecules provides stable performance of the micromotor or can increase the rotation speed.
“Despite low speed, around one rotation per minute, our motor allows us to look at the micromechanics of intelligent soft materials from a different perspective and gives food for thought when it comes to their potential use,” says Klaudia Dradrach from the Photonic Nanostructure Facility. The motor design has been inspired by ring piezoelectric motors, often found in autofocus mechanisms of photographic lenses.
Researchers who have previously demonstrated a light-powered snail robot moving like its natural relatives believe that new intelligent materials combined with advanced fabrication methods will allow them to build further miniature components and drives.
SOURCE: University of Warsaw; https://www.fuw.edu.pl/press-release/news6263.html
