Materials that can produce electricity are at the core of piezoelectric research and the vision of self-powering machines and devices. Nanotechnology researchers are even pursuing nanopiezotronics devices that have the potential of converting biological mechanical energy, acoustic/ultrasonic vibration energy, and biofluid hydraulic energy into electricity, demonstrating a new pathway for self-powering of wireless nanodevices and nanosystems. In addition to miniaturizing piezoelectric devices down to the nanoscale, nanotechnology is also contributing to making next-generation devices more effective. Piezoelectric ceramics for instance generate electrical charge or voltage when they experience stress/strain, and thus are highly efficient at converting mechanical energy into electrical energy. However, ceramics are rigid, which greatly limits the applicability of the energy harvesting. Researchers have now demonstrated that high performance piezoelectric ceramics can be transferred in a scalable process onto rubber or plastic, rendering them flexible without any sacrifice in energy conversion efficiency.