New properties of graphene

Piezoelectric materials generate electricity in response to physical impact, and vice versa. Such materials are used for energy production, manufacture of artificial muscles, high-precision sensors, etc.
Graphene - ultraprochny carbon material, which has found many potential applications. By itself, it does not have piezoelectric properties. However, scientists have found that if you punch the holes with triangular graphene sheet and attach to a sheet of uniform force, graphene becomes piezoelectric properties. Calculations show that it is the triangular hole, rather than, for example, round, make graphene piezoelectric. Moreover, graphene demonstrates the piezoelectric effect as powerful as the best-known piezoelectric material such as quartz.