IMPACT DETECTION AND RECORDING DEVICE

摘要

Provided is an impact detection and recording device requiring no power supply and capable of detecting one-time impact and recording and holding the one-time impact. The impact detection and recording device comprises: a piezoelectric element (2) for converting impact energy into electric energy and outputting the electric energy; and a ferroelectric memory (3) having a ferroelectric material (4) connected to the piezoelectric element (2) and having one principal surface and the other principal surface opposing to the one principal surface, a first electrode (5) formed on the side of the one principal surface of the ferroelectric material (4), and a second electrode (8) formed on the side of the other principal surface of the ferroelectric material (4). The ferroelectric memory (3) can record at least one of the first and second states derived from electron polarization of the ferroelectric material (4). The capacitance-voltage characteristics of the ferroelectric memory (3) have a hysteresis. In the hysteresis curve of the capacitance-voltage characteristics, when the voltage value at which the largest difference in capacitance occurs between the curve when the voltage is increased and the curve when the voltage is decreased is defined as a threshold voltage (Vth), the threshold voltage (Vth) becomes greater than or less than zero.