title: Characteristics of highly flexible PDMS membranes for long-term mechanostimulation of biological tissue.
abstract: Measurement of mechanical properties of soft biological tissue remains a challenging task in mechanobiology. Recently, we presented a bioreactor for simultaneous mechanostimulation and analysis of the mechanical properties of soft biological tissue samples. In this bioreactor, the sample is stretched via deflection of a flexible membrane. It was found that the use of highly compliant membranes increases accuracy of measurements. Here, we describe the production process and characteristics of thin and flexible membranes of polydimethylsiloxane (PDMS) designed to improve the signal-to-noise ratio of our bioreactor. By a spin-coating process, PDMS membranes were built by polymerization of a two component elastomer. The influence of resin components proportion, rotation duration, and speed of the spinning were related to the membrane mechanics. Membranes of 22 mm inner diameter and 33 to 36 microm thickness at homogeneous profiles were produced. Isolated rat diaphragms served as biological tissue samples. Mechanical properties of the membranes remained constant during 24 h of mechanostimulation. In contrast, time- and strain-dependent mechanical properties of the diaphragms were found.
authors: Division for Experimental Anesthesiology, University Medical Center Freiburg, Baden-Württemberg, Germany.
authors: Caroline
authors: C
authors: Armbruster
authors: Division for Experimental Anesthesiology, University Medical Center Freiburg, Baden-Württemberg, Germany.
authors: Matthias
authors: M
authors: Schneider
authors: Division for Experimental Anesthesiology, University Medical Center Freiburg, Baden-Württemberg, Germany.
authors: Stefan
authors: S
authors: Schumann
authors: Division for Experimental Anesthesiology, University Medical Center Freiburg, Baden-Württemberg, Germany.
authors: Katharina
authors: K
authors: Gamerdinger
authors: Clinical Sensoring and Monitoring, Medical Theoretical Center, Dresden University of Technology, Saxony, Germany.
authors: Maximiliano
authors: M
authors: Cuevas
authors: Institute for Computational Mechanics, Technische Universität München, Bavaria, Germany.
authors: Sophie
authors: S
authors: Rausch
authors: Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Baden-Württemberg, Germany.
authors: Gerhard
authors: G
authors: Baaken
authors: Division for Experimental Anesthesiology, University Medical Center Freiburg, Baden-Württemberg, Germany.
authors: Josef
authors: J
authors: Guttmann
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D019149:Bioreactors; D003627:Data Interpretation, Statistical; D003964:Diaphragm / Q000502:physiology; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D066298:In Vitro Techniques; D008297:Male; D008422:Materials Testing / Q000295:instrumentation*; D008567:Membranes, Artificial; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical; D013718:Tensile Strength; D041623:Tomography, Optical Coherence
chemical_list: D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; C013830:baysilon