Fluctuation-induced forces between inclusions in a fluid membrane under tension
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Updated: May 26, 2026

Atomic Force Microscopy Imaging and Force Spectroscopy of Supported Lipid Bilayers
Published on: July 22, 2015
Hsiang-Ku Lin1, Roya Zandi, Umar Mohideen
1Department of Physics & Astronomy, University of California, Riverside, California 92521, USA.
Abstract:
We develop an exact method to calculate thermal Casimir forces between inclusions of arbitrary shapes and separation, embedded in a fluid membrane whose fluctuations are governed by the combined action of surface tension, bending modulus, and Gaussian rigidity. Each object's shape and mechanical properties enter only through a characteristic matrix, a static analog of the scattering matrix. We calculate the Casimir interaction between two elastic disks embedded in a membrane. In particular, we find that at short separations the interaction is strong and independent of surface tension.
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