Graphene has ultra high piezoresistive gauge factor

We report the first-ever use of graphene as a piezoresistive element in a MEMS device, and report on a giant piezoresistivity in the graphene films used on our devices. Owing to the layer nature and the effective confinement of electrons in two-dimensions, applied strain in the graphene films is likely to create large changes in conductivity as the electrons are forces to traverse larger potential wells along increased bond-lengths or result in modulation of current along grain boundaries and multiple graphene layers. In this paper we report a very high piezoresistive gauge factor of 1.8×10⁴. This gauge factor is orders of magnitude higher than that of most piezoresistive materials used in MEMS. This high value of piezoresistivity could be transformative in reinterpretation of the use of piezoresistivity for various hybrid transduction approaches.