Portable and wearable power generators are promising to address the limitation of short operation time for personal devices. In article number 1700044, Yun Xu, Qiaoqiang Gan, and co‐workers develop a triboelectric nanogenerator using crumpled graphene layers. By increasing the degree of crumpling, higher output power can be generated from smaller devices, revealing the potential to develop wearable charging devices for cell phones, smart bands and smart watches.
