<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "4D Microprinting Based on Liquid Crystalline Elastomers"^^ . "Two-photon laser printing (2PLP) is a disruptive three-dimensional (3D) printing technique that can afford structural fabrication at the submicrometer scale. Apart from constructing static 3D structures, research in fabricating dynamic ones, known as \"4D printing”, is becoming a burgeoning field. 4D printed structures exhibit adaptability or tunability towards their environment through the control of an external stimulus. In contrast to the rapid growth in macroscale fabrication, progress in microprinted actuators has only been scarcely reported. Liquid crystal elastomer (LCE) stands out among the promising classes of smart materials for fabricating microrobotics or microactuators due to its distinct anisotropic property, which enables the printed structures to exhibit automated reversible movements upon exposure to stimuli without environmental limitations. Nevertheless, the use of 2PLP for the manufacture of 4D printed LCE microstructures with high versatility and complexity have presented some challenges, limiting their implementation in final applications. This thesis aims to overcome two main obstacles faced in this regard: first, the limitation of two-photon printable stimuli-responsive materials; and second, the lack of a facile approach for aligning liquid crystal (LC) within three dimensions. \r\nThe first part of this thesis aims on expanding the library of materials used for implementing light responsiveness into LC microstructures, as light provides a higher degree of temporal and spatial control compared to other stimuli. The initial approach has involved incorporation of acrylate-functionalized photoresponsive molecules, such as azobenzene and the donor-acceptor Stenhouse adduct (DASA), into a LC ink using a conventional synthetic method. However, several challenges, such as compatibility with the LC ink, have prevented the achievement of 4D printing via 2PLP. The second approach is based on post-modifying printed LC structures and successfully fabricated microactuators with five different photoresponsive features by individually incorporating each light-absorbing molecule. Furthermore, LC microactuators that exhibit distinct actuation patterns under different colors of light were fabricated by simultaneously implementing orthogonal photoresponsive molecules. \r\nThe second project presented in this thesis focuses on developing a new strategy to induce alignment domains in a more flexible manner, with the aim of spatially tailoring the LC topology of the 3D printed microstructures. This is achieved by microprinting 3D scaffolds based on polydimethylsiloxane (PDMS) to manipulate the alignment directions of LC molecules. Taking advantage of 2PLP to fabricate arbitrary scaffolds, LC alignments, including planar and radial patterns, could be introduced freely and simultaneously in three-dimensional space with varying degrees of complexity. The applicability of this alignment approach was demonstrated by fabricating responsive LC microstructures within different PDMS environments, and distinct actuation patterns were observed.\r\nOverall, these two breakthroughs have unveiled a wide array of new potentials for the utilization of responsive LC microsystems with tunable functionalities and customizable actuation responses, that can be applied across various domains and applications."^^ . "2023" . . . . . . . "Li-Yun"^^ . "Hsu"^^ . "Li-Yun Hsu"^^ . . . . . . "4D Microprinting Based on Liquid Crystalline Elastomers (PDF)"^^ . . . "Thesis-Li-Yun Hsu-final_heidox.pdf"^^ . . . "4D Microprinting Based on Liquid Crystalline Elastomers (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "4D Microprinting Based on Liquid Crystalline Elastomers (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "4D Microprinting Based on Liquid Crystalline Elastomers (Other)"^^ . . . . . . "preview.jpg"^^ . . . "4D Microprinting Based on Liquid Crystalline Elastomers (Other)"^^ . . . . . . "medium.jpg"^^ . . . "4D Microprinting Based on Liquid Crystalline Elastomers (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #33586 \n\n4D Microprinting Based on Liquid Crystalline Elastomers\n\n" . "text/html" . . . "540 Chemie"@de . "540 Chemistry and allied sciences"@en . .