Proceedings of nanoGe Fall Meeting 2021 (NFM21)
DOI: https://doi.org/10.29363/nanoge.nfm.2021.110
Publication date: 23rd September 2021
Photo-responsive materials are increasingly attracting attention as they can transduce light energy, which allows no contact stimulation with high spatial and temporal control, into mechanical energy1. Within these materials, Liquid Crystal Elastomers (LCEs) have shown the ability to accomplish large and reversible mechanical actuation under external stimuli. By four-dimensional (4D) printing, the precise programming of the morphology of azobenzene-containing liquid crystalline elastomers (LCEs) that respond to light is possible, achieving high control over the mechanical response. Printing of LCE elements is based on the extrusion of the LCEs precursor through a needle creating forces that align the mesogens along a preferential axis called “director” defined by the needle’s moving direction. In a second phase, the orientation of the mesogens is fixed by photo-polymerization.
Fast mechanical responses have been observed in these 4D printed LCE elements when excited with ultraviolet (UV) light, lifting weights heavier than the LCE element and performing significant work. Both photo-chemical and photo-thermal contributions are recognized, generating forces that can be released by blue light excitation2. In this regard, the ability to print light-responsive elements with programmed morphology and mechanical response, and capable of producing considerable work, open future opportunities for implementing remotely triggered mechanical functions in multiple fields, such as soft robotics and engineering.
The described research study is part of the project PRIME. This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 829010 (PRIME). Funding has also been received from the Spanish MINECO project BIO2017-84246-C2-1-R, Gobierno de Aragon project LMP150_18, and FEDER (EU). D.J.B. thanks the European Research Commission (ERC) Advanced Grant 66999 (VIBRATE). D.L. thanks the Netherlands Organization of Scientific Research (NWO) VENI grant 15135.