Piezoelectric coefficients of cyclo-diphenylalanine microtubes have been evaluated by piezoresponse force microscopy on non-polar and polar sides and were compared to those of linear-diphenylalanine microtubes. It has been shown that cyclo-diphenylalanine microtubes at larger size possess 10 times smaller piezoelectric coefficients.The equipment of Ural Center for Shared Use "Modern Nanotechnology" UrFU has been used. The work was financially supported by the President of the Russian Federation grant for young scientists (Contract 14.Y30.17.2294-MK) and by the Government of the RF (Act 211, Agreement 02.A03.21.0006)
