Studies on Electromechanical foam material (EFOAM) as a potential Sensor and Actuator

Abstract

A novel electromechanical foam (EFOAM) material capable of acting as an electromechanical transducer with integrated functions as a sensoractuator is investigated by manufacturing some samples of the foam and performing some tests, based on the piezo-electric effect in electro-active polymers. The resulting charge, when different known weights are applied to the sample were observed and recorded with a charge amplifier while the actuator sensitivity was also estimated using the micro-scanning laser Doppler vibrometer. EFOAM is manufactured from expancel microspheres and heated by placing the microspheres in glass slides heated up to temperatures of 135 0 C for expansion. Different samples were manufactured and charged using the corona discharge method operating under an electric field of between 11kV/cm to 15kV/cm. EFOAM displayed an electro-mechanical sensitivity of 1nm/V when characterized, and is observed that the piezoelectric nature of EFOAM exists as a characteristic of each cell within the material sample. This novel material offers much promise in the area of production of miniature electromechanical devices which maybe well applied in electroacoustic applications.

Design of a Central Wireless Security System Using Atmega328, ZigBee and Arduino

“…Ultrasonic detectors using frequencies between 15 kHz and 75 kHz, these active detectors transmit ultrasonic sound waves that are inaudible to humans. The Doppler shift principle is the underlying method of operation, in which a change in frequency is detected due to object motion [7]. This is caused when a moving object changes the frequency of sound waves around it.…”

“…motorized bell or electronic siren) and lights (e.g. strobe light) which may be useful for signaling an evacuation notice for people during fire alarms, or where one hopes to scare off an amateur burglar quickly [2,3,7]. Electronic Security System for residential and industrial monitoring of events and actions is achieved by strategically installing sensors and security devices like motion sensors, smoke sensor, security cameras, temperature and humidity sensors at different locations.…”

“…The wireless Home Security System can potentially deter theft caused by burglar or home invasion. The single act of installing sensors on windows and doors can alert home owners of a break-in before a burglar attack is successful [1,5,7]. Motion sensors that monitors entry points on the property can also be programmed to notify Home Security System subscribers of any unwanted activity on their property.…”

“…Installation is mostly doneby experts in the field and some security systems are susceptible to signal interference. Segregated security systems are usually associated with issues of latency and complex management [7]. These systems require higher cost of installation and maintenance and the ratio of cost to accuracy in traditional security systems is relatively high compared to the efficiency of the system in general [7].…”