Preparation of Janus-type actuators based on liquid crystalline elastomers in a mircrofluidic device
Final Report Abstract
It was the intention of this research project to prepare mechanical actuators based on liquid crystalline elastomers (LCEs), which respond to visible light and near UV-light within a microfluidic setup. In the next step then the morphology of these micro-particles should be varied to become Janus-like or tube-like. It was thus the first task to combine the light responsiveness of some known LCEs prepared from azobenzene derivatives with the microfluidic processing. This was not trivial, as the LCE particles are prepared by photo-chemically initiated polymerization, and this process competes with the photo-chemically initiated trans - cis isomerization. This problem could be solved by using radical photo-initiators, which work with visible (red) light. In the next step the desired morphologies of the actuating liquid crystalline particles could be prepared and made to operate at a thermal or photochemical stimulus. The LCE tubes are thereby attractive to pump an internal liquid. The LCE micro-particles of Janus-like shape allow an unsymmetric actuation. In addition they can be self-assembled at liquid-liquid interfaces and transformed into macroscopically actuating surfaces.
Publications
- Influence of an azo-group containing crosslinker on the actuation properties of a photoactuating LCE system. Polymers 8, 435 (2016)
Lukas B. Braun, Torsten G. Linder, Tristan Hessberger and Rudolf Zentel
(See online at https://doi.org/10.3390/polym8120435) - Liquid Crystalline Actuating Janus-Particles by a Co-Flow Microfluidic Synthesis. J. Mat. Chem. C 4, 8778 - 8786 (2016)
T. Hessberger, L. Braun, F. Henrich, C. Müller, F. Gießelmann, C. Serra and R. Zentel
(See online at https://doi.org/10.1039/c6tc03378d) - Microfluidic synthesis of actuating microparticles from a thiol-ene based mainchain liquid crystalline elastomer. Polymers 8, 410 (2016)
Tristan Hessberger, Lukas Braun and Rudolf Zentel
(See online at https://doi.org/10.3390/polym8120410) - Microfluidic Synthesis of Micrometer-Sized Photoresponsive Actuators Based on Liquid Crystalline Elastomers. J. Mat. Chem. C 4, 8670 - 8678 (2016)
L. B. Braun, T. Hessberger and R. Zentel
(See online at https://doi.org/10.1039/c6tc02587k) - UV-free Microfluidic Particle Fabrication at Low Temperature Using ARGET-ATRP as the Initiator System. Macromolecular Reaction Engineering 10, 611 -617 (2016)
Lukas B. Braun, Tristan Hessberger, Christophe A. Serra, Rudolf Zentel
(See online at https://doi.org/10.1002/mren.201600015) - Actuating thermo- and photo-responsive tubes from liquid crystalline elastomers. J. Mat. Chem. C 6, 9093 - 9101 (2018)
Lukas B. Braun, Tristan Hessberger, Eva Pütz, Carsten Müller, Frank Giesselmann, Christophe Serra, Rudolf Zentel
(See online at https://doi.org/10.1039/c8tc02873g) - Interfacial self-assembly of amphiphilic dual temperature responsive actuating Janus particles. Adv. Funct. Mat. 1800629 (2018)
Tristan Hessberger, Lukas Braun and Rudolf Zentel
(See online at https://doi.org/10.1002/adfm.201800629)
