HIGH RESOLUTION 3D LASER WRITING FOR LIQUID

HIGH RESOLUTION 3D LASER WRITING FOR LIQUID CRYSTALLINE
ELASTOMER MICROSTRUCTURES
Camilla Parmeggiania,b Daniele Martellaa,c, Hao Zenga, Piotr Wasylczyka,
Giacomo Cerrettia, Jean-Christophe Gomez Lavocata, Chih-Hua Hoa,
Diederik S. Wiersmaa,b
a
European Laboratory for Non-Linear Spectroscopy (LENS),
Università degli Studi di Firenze, via N. Carrara 1, 50019 Sesto F.no (FI), Italy
b
CNR-INO, U.O.S. Sesto Fiorentino, via N. Carrara 1, 50019 Sesto F.no (FI), Italy
c
Dipartimento di Chimica “Ugo Schiff”, Università degli Studi di Firenze,
via della Lastruccia 3-13, 50019 Sesto F.no (FI), Italy
Liquid Crystalline Elastomers (LCEs) have been considered as smart artificial materials
performing reversible shape-changing in response to external stimuli [1]. Recently,
much effort has been put into reducing the elastomeric structures towards the submillimeter level, specifically for applications in micro-fluidics and robotics. The true
micro scale calls for new, simple and repeatable fabrication technologies to create LCE
structures both in terms of the overall shape as well as the molecular orientation. Direct
laser writing (DLW) is one of the technologies for fabricating 3D polymeric structures
down to sub-micron resolution. In the early reports on the laser-written LCE structures,
the resolution of the process and the control of molecular alignment were limited. Most
importantly, the true 3D capabilities of DLW in Liquid Crystalline Elastomers, have
never been demonstrated.
Here we present 3D LCE structures – rings, woodpiles, etc. - fabricated by two-photon
absorption direct laser writing with sub-micron resolution and, at the same time,
maintaining the desired molecular orientation [2]. With the same technique
Photoresponsive LCEs can be prepared including photosensitive molecules, such as
azobenzene, inside the chains or dispersed in the polymers [3]. These results lay the
foundations for creating 3D, micron-sized, light-controlled LCE structures fundamental
building blocks in micro-robotics.
Acknowledgements. The research leading to these results has received funding from the European
Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC
grant agreement n° [291349] on photonic micro robotics.
____
[1] C. Ohm, M. Brehemr, R. Zentel, Adv. Mater., 2010, 22, 3366.
[2] H. Zeng, D. Martella, P. Wasylczyk, G. Cerretti, J.-C. Gomez Lavocat, C.-H. Ho, C. Parmeggiani, D.
S. Wiersma, Adv. Mater., 2014, DOI: 10.1002/adma.201305008.
[3] T. Ikeda, T. Ube, Materials Today, 2011, 14, 480.

Download Report