Patterned Microstructure Fabrication: Polyelectrolyte Complexes vs Polyelectrolyte Multilayers.
Polyelectrolyte complexes (PEC) are formed by mixing the solutions of oppositely charged polyelectrolytes, which were hitherto deemed "impossible" to process, since they are infusible and brittle when dry. Here, we describe the process of fabricating free-standing micro-patterned PEC films containing array of hollow or filled microchambers by one-step casting with small applied pressure and a PDMS mould. These structures are compared with polyelectrolyte multilayers (PEM) thin films having array of hollow microchambers produced from a layer-by-layer self-assembly of the same polyelectrolytes on the same PDMS moulds. PEM microchambers "cap" and "wall" thickness depend on the number of PEM bilayers, while the "cap" and "wall" of the PEC microchambers can be tuned by varying the applied pressure and the type of patterned mould. The proposed PEC production process omits layering approaches currently employed for PEMs, reducing the production time from ~2 days down to 2 hours. The error-free structured PEC area was found to be significantly larger compared to the currently-employed microcontact printing for PEMs. The sensitivity of PEC chambers towards aqueous environments was found to be higher compared to those composed of PEM.
Micro/Nano Technology Research Centre, Harbin Institute of Technology, Yikuang Street 2, Harbin 150080, China.|School of Engineering and Materials Science, Queen Mary University of London, Mile End, Eng, 215, London, E1 4NS, United Kingdom.
Meiyu
M
Gai
Micro/Nano Technology Research Centre, Harbin Institute of Technology, Yikuang Street 2, Harbin 150080, China.
Johannes
J
Frueh
National Research Tomsk Polytechnic University, RASA Center in Tomsk, Department of Experimental Physics, Tomsk, 634050, Russia.
Valeriya L
VL
Kudryavtseva
School of Engineering and Materials Science, Queen Mary University of London, Mile End, Eng, 215, London, E1 4NS, United Kingdom.
Rui
R
Mao
Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way, Innovis, 08-03, 138634, Singapore.
Maxim V
MV
Kiryukhin
School of Engineering and Materials Science, Queen Mary University of London, Mile End, Eng, 215, London, E1 4NS, United Kingdom.
Gleb B
GB
Sukhorukov