  Graphene can collect energy from the ambient heat and convert it to
electricity, which makes it an ideal candidate for the fabrication of
self-powered devices. However, this technology is suffering the high cost,
which limits the practical use of it. In this work, we demonstrated that the
cost can be reduced by using low cost reduced graphene oxide (RGO), graphite
electrodes and low cost glass substrates. The results showed that this
technology can be of practical value for the "battery" industry.
