Dr. Michael Kappl

Michael Kappl was born Aug 31st, 1963 in Regensburg. He studied physics from 1983-1990 at the University of Regensburg and the Technical University of Munich. From 1991 to 1996 he did his PhD thesis work in Prof. Ernst Bamberg's group at the Max-Planck-Institute of Biophysics in Frankfurt, on transport kinetics of the Na+-Ca2+exchanger membrane protein. From 1997 to 1998 he did one year of postdoctoral research at the University of Mainz in the group of Prof. Butt. From 1998 - 2000 he was working as a consultant for Windows network solutions at the Pallas Soft AG, Regensburg. He rejoined the group of Prof. Butt in August 2000 at the University of Siegen.

Since 2002 he is group leader at the MPI-P, working in the fields of surface forces, wetting and characterization of mechanical properties on the micro- and nanoscale.

In addition he is heading the Focused Ion Beam Service Lab, providing service for nanostructuring, cross-sectioning of samples, preparation of TEM lamella, and 3D tomography.

Research Interests

Surface forces and mechanics on nano- and microscale

The behavior of objects in the micro- and nanoworld is dominated by surfaces forces rather than gravitation or inertia. With the increasing relevance of micro- and nanotechnology, a profound understanding of the forces acting between surfaces is of prominent importance. We use atomic force microscopy (AFM) based techniques and nanoindentation to measure surfaces forces and probe mechanical properties on the micro- and nanoscale.


On superomniphobic surfaces, liquids can form spherical droplets with minimal contact area to a solid support. We use such a configuration for the production of supraparticles, i.e. spherical particles of some 100 µm to mm in size, from colloidal dispersions.

We design new surfaces to boost condensation efficiency of heat exchangers or improve the performance of membranes use in seawater desalination by membrane distillation.

Selected Publications

Díaz, D.; Li, X.; Bista, P.; Zhou, X.; Darvish, F.; Butt, H.-J.; Kappl, M.: Self-generated electrostatic forces of drops rebounding from hydrophobic surfaces. Physics of Fluids 35 (1), 017111 (2023)
Butt, H.-J.; Liu, J.; Koynov, K.; Straub, B.; Hinduja, C.; Roismann, I.; Berger, R.; Li, X.; Vollmer, D.; Steffen, W. et al.; Kappl, M.: Contact angle hysteresis. Current Opinion in Colloid & Interface Science 59, 101574 (2022)
Xing, Y.; Xu, M.; Gui, X.; Cao, Y.; Rudolph, M.; Butt, H.-J.; Kappl, M.: The role of surface forces in mineral flotation. Current Opinion in Colloid & Interface Science 44, pp. 143 - 152 (2019)
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