@article{ZhangSauterFangetal.2015,
  author    = {Zhang, Quanchao and Sauter, Tilman and Fang, Liang and Kratz, Karl and Lendlein, Andreas},
  title     = {Shape-Memory Capability of Copolyetheresterurethane Microparticles Prepared via Electrospraying},
  series = {Macromolecular materials and engineering},
  volume    = {300},
  journal   = {Macromolecular materials and engineering},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1438-7492},
  doi       = {10.1002/mame.201400267},
  pages     = {522 -- 530},
  year      = {2015},
  abstract  = {Multifunctional thermo-responsive and degradable microparticles exhibiting a shapememory effect (SME) have attracted widespread interest in biomedicine as switchable delivery vehicles or microactuators. In this work almost spherical solid microparticles with an average diameter of 3.9 +/- 0.9 mm are prepared via electrospraying of a copolyetheresterurethane named PDC, which is composed of crystallizable oligo(p-dioxanone) (OPDO) hard and oligo(e-caprolactone) (OCL) switching segments. The PDC microparticles are programmed via compression at different pressures and their shapememory capability is explored by off-line and online heating experiments. When a low programming pressure of 0.2 MPa is applied a pronounced thermally-induced shape-memory effect is achieved with a shape recovery ratio about 80\%, while a high programming pressure of 100 MPa resulted in a weak shape-memory performance. Finally, it is demonstrated that an array of PDC microparticles deposited on a polypropylene (PP) substrate can be successfully programmed into a smart temporary film, which disintegrates upon heating to 60 degrees C.},
  language  = {en}
}
@article{FangGouldLysyakovaetal.2018,
  author    = {Fang, Liang and Gould, Oliver E. C. and Lysyakova, Liudmila and Jiang, Yi and Sauter, Tilman and Frank, Oliver and Becker, Tino and Schossig, Michael and Kratz, Karl and Lendlein, Andreas},
  title     = {Implementing and quantifying the shape-memory effect of single polymeric micro/nanowires with an atomic force microscope},
  series = {ChemPhysChem : a European journal of chemical physics and physical chemistry},
  volume    = {19},
  journal   = {ChemPhysChem : a European journal of chemical physics and physical chemistry},
  number    = {16},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1439-4235},
  doi       = {10.1002/cphc.201701362},
  pages     = {2078 -- 2084},
  year      = {2018},
  abstract  = {The implementation of shape-memory effects (SME) in polymeric micro- or nano-objects currently relies on the application of indirect macroscopic manipulation techniques, for example, stretchable molds or phantoms, to ensembles of small objects. Here, we introduce a method capable of the controlled manipulation and SME quantification of individual micro- and nano-objects in analogy to macroscopic thermomechanical test procedures. An atomic force microscope was utilized to address individual electro-spun poly(ether urethane) (PEU) micro- or nanowires freely suspended between two micropillars on a micro-structured silicon substrate. In this way, programming strains of 10 +/- 1\% or 21 +/- 1\% were realized, which could be successfully fixed. An almost complete restoration of the original free-suspended shape during heating confirmed the excellent shape-memory performance of the PEU wires. Apparent recovery stresses of sigma(max,app)=1.2 +/- 0.1 and 33.3 +/- 0.1MPa were obtained for a single microwire and nanowire, respectively. The universal AFM test platform described here enables the implementation and quantification of a thermomechanically induced function for individual polymeric micro- and nanosystems.},
  language  = {en}
}