Light-controlled microrobots take a leap forward
The members of the Smart Photonic Materials group at Tampere University of Technology (TUT) have achieved a breakthrough in reconfiguring light-controlled materials and thereby gained a greater degree of control over their movements. The results of this research were published in the prestigious Nature Communications journal.
Researchers employ UV light to program the shape the material adapts, and then elicit the different types of movements by shining red light on the material.
For the past few years, researchers at TUT have been developing light-controlled materials that change their shape, length or thickness in response to light. These materials have a broad range of potential applications in microrobotics and in the development of tunable optical materials. In a paper titled "Reconfigurable photoactuator through synergistic use of photochemical and photothermal effects", which was recently published in Nature Communications, the researchers describe how light-controlled materials can be reconfigured.
Light-controlled materials typically exhibit only one pre-determined state of deformation under a specific stimulus. For example, the material may bend or twist, but a single sample cannot do both. The new method enables researchers to employ UV light to program the shape the material adapts, and then elicit the different types of movements by shining red light on the material.
”Our concept for developing this material is actually quite simple. It is based on a combination of two well-known light-induced control mechanisms. No one has ever tried this before, despite, or maybe because of, the simplicity of the underlying idea. Our results are a good example of how novel results can be achieved by combining something known in a new way,” says Academy Research Fellow Arri Priimägi who heads the Smart Photonic Materials group at TUT.
Scientific curiosity generates new ideas
Academy Research Fellow Arri Priimägi heads the Smart Photonic Materials group at TUT.
Light-controlled polymers are a new approach, for example, to the field of soft robotics, and new ideas for both fundamental and applied research crop up all the time.
“The driving force behind our research is not so much applications but scientific curiosity and our need to understand all the possibilities of this technology. Of course, reconfigurable and stimuli-responsive materials have applications in microrobotics, biomaterials science and photonics. These are all areas where TUT enjoys a strong reputation and where the opportunities for collaboration are vast,” says Priimägi.
The previous achievements of Priimägi’s Smart Photonic Materials group include, among others, an optical flytrap that was inspired by the way the Venus flytrap ensnares its prey. The optical flytrap is a small elastomer strip – less than one centimetre in length – that is glued onto an optical fibre into which blue light is coupled. When an object in the flytrap’s field of view reflects light onto the elastomer surface, the strip bends itself around the object, capturing it like a Venus flytrap. The optical flytrap is able to lift hundreds of times its own weight.
The research published in Nature Communications was conducted by Markus Lahikainen, who undertook the research for his doctoral dissertation, and PhD Hao Zeng, who holds a postdoctoral research position funded by the Academy of Finland. The research was sponsored by the European Research Council (ERC).