Fig. 5.

2D graphene films obtained by CVD used for piezoresistive pressure sensors. a Schematic illustration of the fabrication procedure of a tactile sensor composed of 2D graphene films and a PET substrate. Reproduced with permission from Ref. [62]. Copyright 2018 Springer Science + Business Media, LLC, part of Springer Nature. b Optical photograph of an ultrathin, transparent and flexible tactile sensor. Inset: The geometric dimension of the sensor. c Sensitivity of the device to longitudinal displacement at different axial distances of 5, 10, 15, and 20 mm. Reproduced with permission from Ref. [58]. Copyright 2017 The Royal Society of Chemistry