Graphene-like substance generates electricity when stretched

Certain materials exhibit what are called piezoelectric characteristics, meaning they develop electric charges when stretched or compressed. In general, the piezoelectric materials we use are large crystals. But researchers have predicted that a substance that forms single-atom-thick molecules—MoS₂—would be strongly piezoelectric. And now researchers have studied these effects experimentally, demonstrating that the number of layers and their orientation have a big impact on the substance’s piezoelectric characteristics.