ENERGY HARVESTING FROM AMBIENT VIBRATION FOR REMOTE VIBRATION MONITORING WITH A SELF-POWERED NANOTUBE BASED SENSOR

摘要

Harvesting energy from ambient vibration in the context of supplying power to a sensor for remote vibration monitoring is presented in this paper. The sensor is powered by the same vibration that is being measured. A transducer, which converts mechanical energy of the structural vibration to electrical energy, powers the system. The transducer which represents the energy supply component in the system is considered as an electro-magnetic scheme with a moving magnet and a coil. The power obtained form the harvested energy is supplied to a nano-electromechanical capacitive sensor. In this sensor, vibration sensing is carried out by detecting the oscillations of Carbon Nanotubes (CNTs). The CNTs are excited when they are subjected to a base motion corresponding to the measured vibration. Acquisition of the sensor signal is performed by a capacitance circuit, using the electric charge generated in the CNTs. A modulation in the CNT's charge, due to changes in the capacitance, leads to a modulation in the CNT's conductance. This device is particularly useful for precise and effective wireless sensing of vibration and structural condition monitoring in hostile or inaccessible environments with little or no maintenance.