Nano-Spintronics Group, TU Chemnitz
Department of Materials for Nanoelectronics Designing smart carriers for biosensors, tissue engineering,and directed cell growth by teaming up semiconductor wafers from micro/nano-electronics and polymer supports from biotechnology Heidemarie Schmidt1 Coauthors Martin Mller2 Katarzyna Wiesenhtter3 Birgit Urban2
Anne-Dorothea Mller4 Ilona Skorupa1,3 Wolfgang Skorupa3 Michal Rb5 Oliver G. Schmidt1,6 1TU Chemnitz, Reichenhainer Strae 39, Chemnitz, Germany 2Leibniz-Institut fr Polymerforschung Dresden e.V., Hohe Str. 6, Dresden 3 HZDR e.V., Bautzner Landstrasse 400, Dresden, Germany 4Anfatec Instruments AG, Melanchthonstr. 28, Oelsnitz (V), Germany 5FH Jena, Fachbereich SciTec, Carl-Zeiss-Promenade 2, Jena, Germany 6IFW Dresden, Helmholtzstrae 20, Dresden, Germany Collaborations & Acknowledgments
K. Wiesenhtter, I. Skorupa, U. Wiesenhtter, A. Kolitsch, W. Skorupa, J. Raff/ Helmholtz-Zentrum Dresden-Rossendorf O.G. Schmidt/ TU Chemnitz, IFW Dresden M. Rb/ EAH Jena A.-D. Mller/ Anfatec Instruments AG J. Meyer, D. Teichmann, S. Friedrich-Lbelt, K. Rosenkranz, T. Frster/ Ascenion GmbH M. Mller, P. Uhlmann/ IPF Dresden A.-K. Meyer/ Klinik fr Neurologie, TU Dresden J. Pahnke/ Section of Neuropathology, University of Oslo O. Deschaumes, C.Bartic/ Soft Matter and Biophysics, KU Leuven G. Ettenberger/ Pharma, Medizinprodukte und Hygiene, OFI Wien F.W. Falkenberg / CIRES GmbH Outlook Polarizable materials and electrostatic forces
Charge-patterned silicon wafers Detection of surface-near electrostatic forces (SNEF) Carriers for nonlocal and local adsorption of polarizable materials PolCarr carriers for novel applications in life sciences Summary Polarizable materials and electrostatic forces
+ - + - Polarizable materials with electric dipole p
Molecule where electrons are concentrated in one place has instantaneous dipole p Molecule with two atoms with different electronegativity has permanent dipole p Molecule where electrons are repelled by permanent dipole of another molecule has induced dipole p Water molecule in vapour, p=1.85 D Cis isomer, p=1.90 D Trans isomer, p=0 D 6 - Electrostatic forces F + + E - - p Charges create electric field E.
Long-range ( nm) Coulomb force F between charges Dipole moment p tends to align in an electric field E + - E p - - + No labeling of polarizable material needed. Many molecules and biomaterials are polarizable. Electrostatic forces between molecules
Attractive force Repulsive force - + + Anionic polymer Cationic polymer Cationic polymer Advances in Polymer Science 255 & 256 (Ed.: Martin Mller), Springer, 2014 Charge-patterned silicon wafers Small charge/area concentration
Bottle battery consisting of 25 Leyden jars (inside (+) & outside (-) metal-coated glas) (Deutsches Museum Mnchen, Inv. Nr. 3920) Frictional electrostatic generator negative (-) charge on rasps positive (+) charge on glass plate Leyden jar (battery) Charges/area: e/m2 1 e/(100 nm x100 nm) Large charge/area concentration
F - F + 200 kV DANFYSIK 1090, High current ion implanter Implanted silicon wafer Charges/area: e/m2 1 e/(1 nm x1 nm) 500 kV ion implanter Length scale:1 mm - 1 mm - 1 nm Detection of surface-near electrostatic forces (SNEF) Probing SNEF by KPFM Kelvin probe force microscopy (KPFM)
Minimization of electrostatic forcesacting on the cantilever (vibration amplitude fac) by applying the appropriate KPFM bias UK to the sample backside. Topography (resonance frequency fr, vibration amplitude ~10 nm) and KPFM bias UK (operation frequency fac, vibration amplitude< 20 pm) probed simultaneously. Probing SNEF by KPFM Minimization of the SNEF
by accumulation of mobile majority charge carriers in the surface region of the doped semiconductor KPFM bias applied to sample backside is related with energy difference between Fermi energy EF and respective band edge [2] Picture: Sander Mnster, Kunstkosmos Doped Si cantilevers (NSC15, k=46 N/m): fac=5 kHz-130 kHz < fr=265 kHz-400 kHz C. Baumgart, M. Helm, H. Schmidt, Phys. Rev. B 80 (2009) Carriers for nonlocal and local adsorption of polarizable materials: 3 Proof-of-Concept (PoC) Nonlocal adsorption of polarizable material
Carrier A: Si substrate with polyelectrolyte coating T.J. Gnther, M. Suhr, J. Raff, K. Pollmann, Immobilization of microorganisms for AFM studies in liquids, RCS Adv. 4 (2014) 51156 PoC with microorganisms on carrier A
A Viridibacillus arvi JG-B58 B Lysinibacillus sphaericus JG-B53, OD600=0.05 C E.coli , OD600=0.10 D E.coli , OD600=0.05 OD600: optical density of cells in a 600 nm Successful immobilization for AFM studies in liquids T.J. Gnther, M. Suhr, J. Raff, K. Pollmann, RCS Adv. 4 (2014) Nonlocal adsorption of polarizable material
Carrier B: Si cantilever with SiO2 coating O. Bumchen et al., Vom Photolack zum Gecko, Physik Journal 14 (2015) 37-42 Force F increases with decreasing SiO2 thickness
PoC with bacteria on carrier B Hydrophilic surface Hydrophobic surface Frequency in percent Frequency in percent Adhesive power in nN Adhesive power in nN Force F increases with decreasing SiO2 thickness O. Bumchen et al., Vom Photolack zum Gecko, Physik Journal 14 (2015) 37-42 Dipping/spin-coating
Local adsorption of polarizable material Carrier C: PolCarr carrier Charge-patterned silicon wafer Dipping/spin-coating in/of solution with polarizable material Local attachment of polarizable material on PolCarr carrier H. Schmidt, S. Habicht, S. Feste, A.-D. Mller, O.G. Schmidt, Appl. Surf. Sci. 281 (2013) Diethylaminoethyl-Dextran-FITC (DEAE-FITC)
Local adsorption of polarizable material Diethylaminoethyl-Dextran-FITC (DEAE-FITC) (=10-20 nm (pH=9), l=200 nm (pH=4)) Local P-implantation of n+-Si stripes (5 mm width, 15 mm periodicity) into n-Si Dipping at pH=11 (1 mg/ml) Rinsing (5 min, dest. water) Drying (10 min, 50C) pH=9 pH=4 Advances in Polymer Science 255 & 256 (Ed.: Martin Mller), Springer, 2014 H. Schmidt, S. Habicht, S. Feste, A.-D. Mller, O.G. Schmidt, Appl. Surf. Sci. 281 (2013) Positively charged molecule (DEAE-FITC)
Cationic polymer diethylaminoethyl-Dextran-FITC (DEAE-FITC) + pH=9 pH=4 + Monomer molar mass: 231g/mol Polymer molar mass: g/mol Charges per monomer unit: 0.5 Branched topology, Labeled with Fluoresceinisothiocyanat/FITC Coiled chain (pH=9): =10-20 nm Elongated chain (pH=4): l=200 nm Advances in Polymer Science 255 & 256 (Ed.: Martin Mller), Springer, 2014 PoC with DEAE-FITC on carrier C
10 mm 100% coating of n+-Si-stripes with DEAE-FITC Standard Si wafer: