Abstract
For the first time, the yield strength of thin-film parylene-C is measured from membrane load-deflection experiments and surface profile analysis. To do so, the onset pressure which causes plastic deformation of the membrane is first experimentally measured. Then a new 2-step displacement model, together with the energy minimization technique [1], is developed to convert the onset pressure to the yield strength on the pre-stressed parylene membrane under a uniform pressure loading. The results depict a Yield Strength of 59 MPa (or 0.012 of strain) for thin-film parylene-C in comparison to 55 MPa reported by parylene vendor (measured from large samples) [2]. To double check with the result, the balloon model [3] is further used to compare with the stress value from our model at the center of parylene membranes and good agreements are obtained.
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This work is supported by the NSF Center for Neuromorphic Systems Engineering (CNSE) at Caltech.
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Shih, C.Y., Harder, T.A. & Tai, Y.C. Yield strength of thin-film parylene-C. Microsystem Technologies 10, 407–411 (2004). https://doi.org/10.1007/BF02637112
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DOI: https://doi.org/10.1007/BF02637112