Simulation-based design of thermally-driven actuators using liquid crystal elastomers

ABSTRACT

Liquid crystal elastomers (LCEs) are a class of soft functional materials which exhibit complex mechanical responses to external stimuli. Their promise for technological applications is difficult to realise in practice due to the complexity of design, fabrication and performance quantification of these materials. In order to address these issues, simulation-based methods are necessary to both enhance and accelerate the design process, compared to traditional experimentation alone. This work presents such an approach using a hyperelastic solid mechanics model and experimental measurement of material parameters for a thermotropic LCE. The simulation method is validated using existing experimental data of the thermomechanical response of an LCE-based cantilever resulting from a hybrid-aligned nematic texture imposed during crosslinking. The validated method is then used to perform a proof-of-concept design process of an LCE multilegged gripper in order to determine optimal design parameters for gripper performance. The simulation method and results presented in this work represent a significant step towards simulation-based design of LCE materials, which has the potential to overcome the complexity and cost of the LCE design process.

Graphical Abstract

KEYWORDS:

• Liquid crystal elastomers
• functional materials
• simulation
• actuators

Acknowledgments

This work was made possible by the Natural Sciences and Engineering Research Council of Canada (NSERC), Compute Ontario, and Compute Canada. Experimental data for deformation of uniform planar-aligned LCN films and curvature response to temperature of hybrid-aligned cantilevers were collected by Shahsavan during a visit to Kent State University. Thanks to Professor Antal Jákli for hosting the visit and making his lab available.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Canada Foundation for Innovation; Natural Sciences and Engineering Research Council of Canada; the Ontario Graduate Scholarship.