But some crystalline materials don't possess a center of symmetry making them candidates for piezoelectricity.

但是一些晶体材料不具有对称中心，这使它们成性的候者。

There are already train stations that use passengers' footsteps to power the ticket gates and displays and a dance club where piezoelectricity helps power the lights.

有火车站使用乘客的脚步检票口和显示屏供，还有一个舞蹈俱乐部使用技术灯供。