Soft Objects

We study the deformation and dynamics of soft objects. We use microfluidic channels to hydrodynamically deform healthy and diseased red blood cells and observe their morphology and trajectories. We also exploit the interaction of soft objects with channel boundaries to separate different cell types from each other such as circulating tumor cells form red blood cells.
Synthetic and biological cells are squeezed in tapered glass capillaries and their mechanical response to external pressure is analyzed.


Hydrodynamic deformation of an RBC in a microchannel

Hydrodynamic deformation of an RBC in a microchannel




Geislinger, T. M., and Franke, T. (2014) Hydrodynamic lift of vesicles and red blood cells in flow — from Fåhræus & Lindqvist to microfluidic cell sorting. Advances in Colloid and Interface Science, 208, pp. 161-176. (doi:10.1016/j.cis.2014.03.002)

Geislinger, T.M., and Franke, T. (2014) Filtern war gestern: Sortierung von zirkulierenden Tumorzellen in Lab-on-a-Chip Systemen. GIT Labor-Fachzeitschrift, 4, pp. 50-52.

Geislinger, T. M., Chan, S., Moll, K., Wixforth, A., Wahlgren, M., and Franke, T. (2014) Label-free microfluidic enrichment of ring-stage Plasmodium falciparum-infected red blood cells using non-inertial hydrodynamic lift. Malaria Journal, 13(1), p. 375. (doi:10.1186/1475-2875-13-375)

Geislinger, T. M., and Franke, T. (2013) Sorting of circulating tumor cells (MV3-melanoma) and red blood cells using non-inertial lift. Biomicrofluidics, 7(4), 044120. (doi:10.1063/1.4818907)

Geislinger, T.M., Eggart, B., Braunmüller, S., Schmid, L., and Franke, T. (2012) Separation of blood cells using hydrodynamic lift. Applied Physics Letters, 100(18), p. 183701. (doi:10.1063/1.4709614)


Capillary micromechanics:

Wyss, H. M. et al. (2011) Biophysical properties of normal and diseased renal glomeruli. American Journal of Physiology: Cell Physiology, 300(3), C397-C405. (doi:10.1152/ajpcell.00438.2010)

Wyss, H. M., Franke, T., Mele, E., and Weitz, D. A. (2010) Capillary micromechanics: measuring the elasticity of microscopic soft objects. Soft Matter, 6(18), pp. 4550-4555. (doi:10.1039/C003344H)

Wyss, H. M., Mattsson, J., Franke, T., Fernandez-Nieves, A., and Weitz, D. A. (2011) Mechanics of single microgel particles. In: Fernandez-Nieves, A., Wyss, H. M., Mattsson, J. and Weitz, D. A. (eds.) Microgel Suspensions: Fundamentals and Applications. Wiley-VCH: Weinheim, pp. 311-325. ISBN 9783527321582 (doi:10.1002/9783527632992.ch12)


Hydrodynamic Deformation

Noguchi, H., Gompper, G., Schmid, L., Wixforth, A., and Franke, T. (2010) Dynamics of fluid vesicles in flow through structured microchannels. Europhysics Letters, 89(2), p. 28002. (doi:10.1209/0295-5075/89/28002)

Braunmüller, S., Schmid, L., Sackmann, E., and Franke, T. (2012) Hydrodynamic deformation reveals two coupled modes/time scales of red blood cell relaxation. Soft Matter, 8(44), p. 11240. (doi:10.1039/C2SM26513C)

Braunmüller, S., Schmid, L., and Franke, T. (2011) Dynamics of red blood cells and vesicles in microchannels of oscillating width. Journal of Physics: Condensed Matter, 23(18), p. 184116. (doi:10.1088/0953-8984/23/18/184116)

Franke, T., Hoppe, R. H. W., Linsenmann, C., Schmid, L., Willbold, C., and Wixforth, A. (2011) Numerical simulation of the motion of red blood cells and vesicles in microfluidic flows. Computing and Visualization in Science, 14(4), pp. 167-180. (doi:10.1007/s00791-012-0172-1)


Viscoelasticity and properties of lipid vesicles and membranes

Franke, T., Leirer, C., Wixforth, A., and Schneider, M. F. (2009) Phase transition induced adhesion of giant unilamellar vesicles. ChemPhysChem, 10(16), pp. 2858-2861. (doi:10.1002/cphc.200800555)

Franke, T., Leirer, C. T., Wixforth, A., Dan, N., and Schneider, M. F. (2009) Phase-transition- and dissipation-driven budding in lipid vesicles. ChemPhysChem, 10(16), pp. 2852-2857. (doi:10.1002/cphc.200900658)

Gruhn, T., Franke, T., Dimova, R., and Lipowsky, R. (2007) Novel method for measuring the adhesion energy of vesicles. Langmuir, 23(10), pp. 5423-5429. (doi:10.1021/la063123r)

Franke, T., Lipowsky, R., and Helfrich, W. (2006) Adhesion of lipid membranes induced by CrCl3. Europhysics Letters (EPL), 76(2), pp. 339-345. (doi:10.1209/epl/i2006-10249-7)

Lipowsky, R., Brinkmann, M., Dimova, R., Franke, T., Kierfeld, J., and Zhang, X. (2005) Droplets, bubbles, and vesicles at chemically structured surfaces. Journal of Physics: Condensed Matter, 17(9), S537-S558. (doi:10.1088/0953-8984/17/9/015)

Franke, T., Helfrich, W., and Lipowsky , R. (2004) Binding transition of PC membranes mediated by chromium ions. Biophysical Journal, 86(1), 382A.


Franke, T., Schmid, L., Weitz, D. A., and Wixforth, A. (2009) Magneto-mechanical mixing and manipulation of picoliter volumes in vesicles. Lab on a Chip, 9(19), pp. 2831-2835. (doi:10.1039/b906569p)

Forsyth, A. M., Braunmüller, S., Wan, J., Franke, T., and Stone, H. A. (2012) The effects of membrane cholesterol and simvastatin on red blood cell deformability and ATP release. Microvascular Research, 83(3), pp. 347-351. (doi:10.1016/j.mvr.2012.02.004)


Book Sections

Franke, T., Hoppe, R. H.W., Linsenmann, C., and Wixforth, A. (2012) Projection based model reduction for optimal design of the time-dependent stokes system. In: Leugering, G., Engell, S., Griewank, A., Hinze, M., Rannacher, R., Schulz, V., Ulbrich, M. and Ulbrich, S. (eds.) Constrained Optimization and Optimal Control for Partial Differential Equations. Series: International Series of Numerical Mathematics (160). Springer Basel: Basel, pp. 75-98. ISBN 9783034801324 (doi:10.1007/978-3-0348-0133-1_5)