Self-powered microsensors that harvest energy from flowing water could result in more accurate and cost-efficient oil exploration. Researchers at the Rensselaer Polytechnic Institute, United States, have found that water flowing over surfaces coated with the nanomaterial graphene can generate small amounts of electricity. The amount of energy would be sufficient to power tiny sensors introduced into water or other fluids, or pumped down into a potential oil well. The injected water, with the microsensors, could detect the presence of hydrocarbons and help uncover hidden pockets of oil and natural gas as it moved through naturally occurring cracks and crevices deep in the earth. According to Nikhil Koratkar, a professor in the Department of Mechanical, Aerospace and Nuclear Engineering, “It’s impossible to power these microsensors with conventional batteries, as the sensors are just too small. So we created a graphene coating that allows us to capture energy from the movement of water over the sensors. While a similar effect has been observed for carbon nanotubes, this is the first such study with graphene. The energy-harvesting capability of graphene was at least an order of magnitude superior to nanotubes. Moreover, the advantage of the flexible graphene sheets is that they can be wrapped around almost any geometry or shape.” The discovery would mean that oil companies would no longer be limited to vertical exploration, but could also explore laterally, providing firms with information about the best location to drill. The details of the study were published in the journal Nano Letters.
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