@article{WuennemannNoyongKreuelsetal.2016,
  author    = {Wuennemann, Patrick and Noyong, Michael and Kreuels, Klaus and Bruex, Roland and Gordiichuk, Pavlo and van Rijn, Patrick and Plamper, Felix A. and Simon, Ulrich and B{\"o}ker, Alexander},
  title     = {Microstructured Hydrogel Templates for the Formation of Conductive Gold Nanowire Arrays},
  series = {Macromolecular rapid communications},
  volume    = {37},
  journal   = {Macromolecular rapid communications},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201600287},
  pages     = {1446 -- 1452},
  year      = {2016},
  abstract  = {Microstructured hydrogel allows for a new template-guided method to obtain conductive nanowire arrays on a large scale. To generate the template, an imprinting process is used in order to synthesize the hydrogel directly into the grooves of wrinkled polydimethylsiloxane (PDMS). The resulting poly(N-vinylimidazole)-based hydrogel is defined by the PDMS stamp in pattern and size. Subsequently, tetrachloroaurate(III) ions from aqueous solution are coordinated within the humps of the N-vinylimidazole-containing polymer template and reduced by air plasma. After reduction and development of the gold, to achieve conductive wires, the extension perpendicular to the long axis (width) of the gold strings is considerably reduced compared to the dimension of the parental hydrogel wrinkles (from approximate to 1 mu m down to 200-300 nm). At the same time, the wire-to-wire distance and the overall length of the wires is preserved. The PDMS templates and hydrogel structures are analyzed with scanning force microscopy (SFM) and the gold structures via scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The conductivity measurements of the gold nanowires are performed in situ in the SEM, showing highly conductive gold leads. Hence, this method can be regarded as a facile nonlithographic top-down approach from micrometer-sized structures to nanometer-sized features.},
  language  = {en}
}
@article{ZhouWuennemannKuhnetal.2016,
  author    = {Zhou, Qihui and Wuennemann, Patrick and Kuhn, Philipp Till and de Vries, Joop and Helmin, Marta and B{\"o}ker, Alexander and van Kooten, Theo G. and van Rijn, Patrick},
  title     = {Mechanical Properties of Aligned Nanotopologies for Directing Cellular Behavior},
  series = {Advanced materials interfaces},
  volume    = {3},
  journal   = {Advanced materials interfaces},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {2196-7350},
  doi       = {10.1002/admi.201600275},
  pages     = {10},
  year      = {2016},
  abstract  = {Tailoring cell-surface interactions is important for the of design medical implants as well as regenerative medicine and tissue engineering materials. Here the single parameter system is transcended via translating hard nanotopology into soft polymeric hydrogel structures via hydrogel imprinting lithography. The response of these cells to the nanotopology of the same dimensions but with different mechanical properties displays unexpected behavior between "hard" tissue cells and "soft" tissue cells.},
  language  = {en}
}
@article{MergelWuennemannSimonetal.2015,
  author    = {Mergel, Olga and Wuennemann, Patrick and Simon, Ulrich and B{\"o}ker, Alexander and Plamper, Felix A.},
  title     = {Microgel Size Modulation by Electrochemical Switching},
  series = {Chemistry of materials : a publication of the American Chemical Society},
  volume    = {27},
  journal   = {Chemistry of materials : a publication of the American Chemical Society},
  number    = {21},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0897-4756},
  doi       = {10.1021/acs.chemmater.5b02740},
  pages     = {7306 -- 7312},
  year      = {2015},
  abstract  = {In this work we present the first e-microgel, whose size can be adjusted by application of an electrochemical potential, as seen by dynamic light scattering (3D-DLS in dependence of equilibrium potential) and scanning force microscopy (SFM). Hereby, polyelectrolyte microgels with attracted electroactive counterions provide an effective platform for the manipulation of the microgel size by electrochemical means. The reversible switching of guest molecules, namely, hexacyanoferrates, between oxidized ferricyanide [Fe(CN)(6)](3-) and reduced ferrocyanide [Fe(CN)(6)](4-), influences the cationic host microgel, poly(N-isopropylacrylamide-co-methacrylamidopropyltrimethylammonium chloride) P(NIPAM-co-MAPTAC), and hence the swelling properties of the microgel. The combination of thermo- and redox-responsiveness in one particle leads to a novel type of multistimuli responsive material. In addition, the use of hydrodynamic voltammetry detects directly the preferred uptake of ferricyanide and enables the determination of the nominal charge ratio (ncr) between microgel and entrapped counterions at different states of switching. Further, electrochemical impedance spectroscopy allows a more detailed mechanistic insight into the microgel modulation.},
  language  = {en}
}