Energy harvesting for self-powered nanosystems

In this article, an introduction is pr esented about the energy harvesting technologies that have potential for powering nanosystems. Our discussion mainly focuses on the approaches other than the well-known solar cell and thermoelectrics. We mainly introduce the piezoelectric nanogenerators developed using aligned ZnO nanowire arrays. This is a potential technology for converting mechanical movement energy (such as body movement, muscle stretching, blood pressure), vibration energy (such as acoustic/ultrasonic wave), and hydraulic energy (such as fl of body fl uid, blood fl ow, contraction of blood vessel, dynamic fl uid in nature) into electric energy for self-powered nanosystems.