Wireless Piezoceramic Energy Harvester
The proposed technology concerns an autonomous sensing node composed of a sensing/actuating unit coupled with a wireless communication system and powered by a piezoceramic vibrational energy harvester. A piezoceramic lead-free energetic autonomous wireless sensing network has potential applications in any environment where there is useful mechanical vibration that can be converted into sufficient energy to power the electro-mechanic parts of network nodes.
The proposed technology, developed in the frame of a co-founded Piedmont regional program (namely VerdePiezo), concerns the production of an autonomous sensing node composed of a sensing/actuating unit coupled with a wireless communication system and powered by a piezoceramic vibrational energy harvester, compliant with the Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment 2002/95/EC (commonly referred to as RoHS) adopted in February 2003 by the European Union.
The device is adequately versatile to be adaptable for different applications, for industrial applications, transportation, automotive and of course space applications.
The piezoelectric device produces an amount of energy sufficient to power small electro-mechanic devices (e.g. microprocessor, sensor, wireless transmission, micro actuators, etc.).
This technology aims to simplify the complexity of advanced systems in terms of wiring, reducing the energy consumption by recovering the by-product vibration energy.
If associated with suitable mechanical resonators, it is possible to store an amount of energy adequate to power a complete small electro-mechanical system.
In the space segment the main use is on-board launchers and spacecraft, with the aim of reducing the harness mass, reducing routing complexity and, at the same time, opening the possibility of placing sensing nodes in remote locations, increasing the health monitoring awareness of the overall system. The heart of the application lies in the development of the piezoelectric material coupled with an optimized mechanical resonator, and in the design of an optimized electronic conditioning unit.
Innovations & Advantages
The use of piezoelectric devices for energy vibrational recovery, although it uses a known technology, is still an innovative sector since it is not in widespread use and the manufacture of such devices is not yet industrialized. Such devices have recently started to appear as commercial products, but they are still immature and with a high price that mitigates against the widespread use of the technology.
Some examples of existing applications are:
• The sidewalks of bridges with a high rate of traffic, where the energy recovered from the steps of the pedestrians is stored for night lighting
• The sidewalks outside the railway station of Shibuya-Tokyo
• Under the dance floor of a nightclub in Rotterdam,
• For the supply of small sensors coupled to industrial machines.
VerdePiezo paves the way to a new device that can simplify the complexity of a system, especially in terms of wiring, allowing the use of active electronic components capable of recovering by-product vibration energy that would be wasted otherwise. It is important to note that this type of technology can be easily rescaled for application in different sectors in which there is a suitable vibration environment. The scale production of such technology will open the door to widespread sensor networks of miniaturized wireless device, that are energetically independent, and that can monitor ubiquitously structures or systems that operate in an environment characterized by vibrations.
Exploitation opportunities for an piezoceramic lead-free energetic autonomous wireless sensing network may be found in any environment where there is useful mechanical vibration that can be converted into sufficient energy to power the electro-mechanic parts of the network nodes.
At the moment, the most promising non-space applications are foreseen in the railway/automotive and heavy industry business.
The railway application can be divided into three main areas:
1. Freight car,
The freight car has no electrical wiring, thus an energy harvesting system is the ideal solution for ball bearings health monitoring, via an accelerometer, or for the monitoring of wheels, shafts and breaks. For a coach, the possibility to place ubiquitous sensors could increase the safety of critical elements as well as the comfort of the passengers. The possibility to embed into the infrastructure (the concept is applicable also for highway and high frequency roads) an energy harvesting device, capable of powering signals or monitoring the health status of the railroad (e.g. monitoring the correct functionality of the switches) would increase the safety of the system even in low urbanized locations.
In the automotive industry, the utilization of such technology would reduce the harness mass, reducing at the same time the integration time and increasing the configuration capability.
Current and Potential Domains of Application
In the space segment the main use is on-board launchers and spacecraft, with the aims to reduce the harness mass, reduce routing complexity and, at the same time, giving the possibility to place sensing nodes in remote locations, increasing the health monitoring awareness of the overall system.
Other non –space promising markets are the railway/automotive and heavy industry business, more specifically for :
1. Freight car,