With the recent advances in wireless and micro electro mechanical systems technology, the demand for portable electronics and sensors is growing rapidly. Because these devices are portable, it becomes necessary that they carry their own power supply. In most cases this power supply is the conventional battery; however, problems can occur while using batteries because of their finite lifespan. For portable electronics, replacing the battery is problematic because the electronics could die at any time and replacement of the battery can become a tedious task. Supplying power through a long cable can be impractical, hard to install and maintain. Advances in integrated circuit manufacturing and low power circuit design have reduced the total power requirements of a sensor node to well below 1 mW.
The sensor network systems provide new services based on the information in the real world. Sensor nodes, which constitute terminals of a sensor network system, measure the environment, such as temperature and humidity. Power consumption of wireless communication is large, so intermittent operation is effective in reducing power consumption. Consequently, sensor nodes have achieved average power consumption on the microwatt order. However, we still have a problem of maintenance cost to change battery manually of every distributed sensor node.
Therefore, the power-free sensor nodes that scavenge its energy from ambient environments (mainly industries) and need no battery are strongly desired. There have been many approaches for ambient-energy scavenging technologies that use solar energy, thermal energy, and environmental vibration energy, of all these scavenging technology from vibration is quite useful. It can be applied for the sensor nodes that monitor the problems of the industrial machines such as machines, motors or monitor the circumstances in the busy traffic roads. However, conventional scavenging technologies from environmental vibration have not yet achieved to supply stable power for continuous operation of sensor nodes. The scavenged powers have reached in 100 microwatt order, but the sensor nodes require 10 mW order power instantly.
For this reason, conventional scavenging technologies are used as a supporting battery that enhance the lifetime of the main battery. In this project, we describe a completely power-free sensor node or low power electronic device that works under small vibration energy scavenged from industrial machines with no battery. The energy harvester consists of a piezoelectric resonator or Piezoelectric Sensors
(click here for Piezoelectric Ceramics: Principles and Applications
) for a vibration-to-electric energy converter, and a power control circuit that store scavenged current charge to supply instant power.
The sensor network systems provide new services based on the information in the real world. Sensor nodes, which constitute terminals of a sensor network system, measure the environment, such as temperature and humidity. Power consumption of wireless communication is large, so intermittent operation is effective in reducing power consumption. Consequently, sensor nodes have achieved average power consumption on the microwatt order. However, we still have a problem of maintenance cost to change battery manually of every distributed sensor node.
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| ADVANCED NANO MATERIAL WHICH PRODUCES ELECTRICAL POTENTIAL BY THE PIEZOELECTRIC PRINCIPLE |
For this reason, conventional scavenging technologies are used as a supporting battery that enhance the lifetime of the main battery. In this project, we describe a completely power-free sensor node or low power electronic device that works under small vibration energy scavenged from industrial machines with no battery. The energy harvester consists of a piezoelectric resonator or Piezoelectric Sensors
(click here for Piezoelectric Ceramics: Principles and Applications) for a vibration-to-electric energy converter, and a power control circuit that store scavenged current charge to supply instant power.