Applications of Piezoelectricity: Home safety device

Abstract

The following piezoelectric security doormat is a safety device based on the piezoelectric effect and its converse. Pressure exerted by the person on the doormat is detected by the piezoelectric plates lined inside the mat. These piezoelectric plates are connected in a parallel orientation to make the doormat more durable because if a single piezoelectric plate becomes dysfunctional, the remaining branches will still work and keep the entire system operational. Once the pressure is detected, an electric charge is generated due to the piezoelectric effect. This electric charge is sensed by the Arduino. The coding of the Arduino is done in such a way that whenever it senses an electrical input, the piezo buzzer attached to it is turned on. This piezoelectric buzzer works on the principle of inverse piezoelectric effect where the voltage difference applied induces mechanical stress on the plates producing vibrations. Thus, the security doormat on sensing pressure difference whenever someone stands on it turns on the buzzer connected to it and therefore, alerts the residents.