▎ 摘　　要

We use micro-Raman spectroscopy to study strain in free-standing graphene monolayers anchored to SiN holes of non-circular geometry. We show that a uniform differential pressure load yields measurable deviations from hydrostatic strain, conventionally observed in radially symmetric microbubbles. A pressure load of 1 bar yields a top hydrostatic strain of approximate to 0.7% and a G(+/-) splitting of 10 cm(-1) in graphene clamped to elliptical boundaries with axes 40 and 20 mu m, in good agreement with the calculated anisotropy Delta epsilon approximate to 0.6% and consistently with recent reports on Gruneisen parameters. The implementation of arbitrary strain configurations by designing suitable boundary clamping conditions is discussed. (C) 2016 Author(s).