Battery-less impact-logging device consisting of a vibration energy scavenger and ferroelectric memory

Energy scavenging from ambient energy sources has been widely researched with a focus on sensors and devices as alternative power sources for batteries. Vibration energy scavenging is of specific interest for a variety of environments in which sinusoidal vibrations or repetitive impacts are present [1]. In addition, a vibration energy scavenger has applicability to an impact sensor because an applied impact is immediately converted to electrical power. If the impact data are stored at the same time in non-volatile memory by the electrical power generated by impact itself, a battery-less impact-logging system is feasible. However, the generated power alone is insufficient for recording impact histories to conventional non-volatile memory. In this work, we focus on a ferroelectric-gate field-effect transistor (FeFET) as a non-volatile memory [2] because an FeFET is able to memorize data with low power consumption and read the data non-destructively.