Related Experiment Video
Updated: Jul 20, 2026

Microfluidic Channel-Based Soft Electrodes and Their Application in Capacitive Pressure Sensing
Published on: March 17, 2023
Freestanding polyelectrolyte films as sensors for osmotic pressure
Marc Nolte1, Ingo Dönch, Andreas Fery
1Max-Planck-Institut für Kolloid und Grenzflächenforschung Wissenschaftspark Golm, 14424 Potsdam, Germany.
Abstract:
Freestanding ultrathin polyelectrolyte-multilayer membranes, transferred to topographically structured polydimethylsiloxane (PDMS), are used as mechanical sensors. Due to the membranes' semipermeability, high-molecular-weight molecules can be either entrapped inside them or excluded, thus generating an osmotic pressure. This leads to a deformation. We investigate the deformation as a function of the osmotic pressure and present an analytical theory that fully describes the data. Thus, osmotic pressures can be determined quantitatively. The individual osmotic-sensitive elements have only microscopic dimensions, and arrays can be easily produced.
Related Concept Videos
Potentiometry: Membrane Electrodes
Osmotic Pressure
Osmosis and Osmotic Pressure of Solutions

