Locomotion of light-driven soft microrobots through a hydrogel via local melting
Authors: Palagi S., Mark A.G., Melde K., Qiu T., Zeng H., Parmeggiani C., Martella D., Wiersma D.S., Fischer P.
Autors Affiliation: Max Planck Institute for Intelligent Systems, Stuttgart, 70569, Germany; Max Planck ETH Center for Learning Systems, Germany; Chemistry and Bioengineering Department, Tampere University of Technology, Finland; European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, 50019, Italy; CNR-INO, Sesto Fiorentino, 50019, Italy; Institut für Physikalische Chemie, Universität Stuttgart, Stuttgart, 70569, Germany
Abstract: Soft mobile microrobots whose deformation can be directly controlled by an external field can adapt to move in different environments. This is the case for the light-driven microrobots based on liquid-crystal elastomers (LCEs). Here we show that the soft microrobots can move through an agarose hydrogel by means of light-controlled travelling-wave motions. This is achieved by exploiting the inherent rise of the LCE temperature above the melting temperature of the agarose gel, which facilitates penetration of the microrobot through the hydrogel. The locomotion performance is investigated as a function of the travelling-wave parameters, showing that effective propulsion can be obtained by adapting the generated motion to the specific environmental conditions.
More Information: This work was in part supported by the European Research Council under the ERC Grant agreements 278213 and 291349. S.P. acknowledges support by the Max Planck ETH Center for Learning Systems.17 July 201KeyWords: Liquid crystals; Melting; Robotics; Wave transmission, External fields; Light driven; Liquid crystal elastomers; Local melting; Microrobots; Mobile microrobots; Specific environmental conditions; Travelling waves, Hydrogels