Energy harvester
Categories
A wideband vibration energy harvester with integrated energy management designed for harsh environment.
14 June 2024
Bistable energy harvesters (BEH) are well adapted devices to deal with the variation of the vibration source frequency spectrum. Indeed, the non-linear motion of this kind of harvester allow to reach a harvesting bandwidth up to 50% of the resonant frequency compared to 1-2% of the resonant frequency typically for conventional linear energy harvesters. CEDRAT TECHNOLOGIES proposes a design using buckled beam and Amplified Piezoelectric Actuator (APA®) technology based on an architecture patented by the USMB. The nonlinear behavior of such a kind of energy harvester has already been studied in the literature and has demonstrated promising results.
Due to the use of buckled beam, the bistable energy harvester is very sensitive to the thermal expansion resulting from the harsh environment. In this paper, it is proposed an improved design to manage the thermal expansion and ensure harvesting capabilities on a wide temperature range from -40°C to +80°C.
Furthermore, an electronic extraction circuit has been implemented to deliver a regulated output voltage to power an IoT. Moreover, this electronic circuit can deal with spontaneous excess of energy by storing it into a supercapacitor or a battery and sink this energy to still powering the IoT when the vibration level decrease. The BEH with the electronic extraction circuit can generate a power of 8mW.
The combination of an athermalized Bistable Energy Harvester with an electronic extraction circuit increases the technological readiness level to be integrated in system subjected to harsh environment like railway application for instance.
Light-controlled mechanisms based on photomobile polymers for seamless integration in demanding environments
14 June 2024
Photomobile polymers (PMP) are active materials that convert light into mechanical movement. They can be used in energy harvesters, light-controlled actuators, or mechanisms. Because they are controlled by light and work without electricity, they offer unique opportunities for designing devices that can be integrated seamlessly and that require virtually no maintenance. This finds interest in fields like nuclear energy, medical implants, biology, space, or Internet of Things (IoT). Cedrat Technologies have designed, built, and tested 3 proof of concept prototypes: a mechanical switch, a mechanical valve, and an optical deflector. The present paper will present these 3 concepts and the tests results in detail.
Mechanical structure with high force amplification ratio for low frequency piezoelectric harvester application
19 June 2023
A mechanical structure based on serial stacking of level arm has been designed in order to amplify the ingoing force of the the harvester system. The outgoing force is applied upon the smart material. The deformation of the mechanical structure is based on flexural pivots using four truncated circular collars. The last amplification is based on the APA® (Amplified Piezoelectric Actuator) shell and already patented solution by Cedrat Technologies. The force amplification structure has been designed upon the request of a small volume allocated (0.3 cm3) and low frequency resonance (20 Hz) harvester
Vibration energy harvesting in aircraft using piezoelectric actuators
19 June 2023
In the aicrft vehicle, a part of the produced energy is transformed into mechanical vibration energy losses. This rue is more than ever true when the need for electrucal energy is a crucial problem. So, systems which are able to transform the mechanical energy in a scavenged electrical energy are very interesting.
A bistable piezoelectric harvester for wideband mechanical frequency excitation
19 June 2023
The developments of autonomous systems such as for self health monitoring, embedded systems are increasingly used in industrial applications. The energy supply is a key point for the development of such systems. Solutions based on battery have limited life time and the power supplies through wires aren’t always appropriate and easy to install. Furthermore, the battery recycling is complex and an expensive process. The researches on power supply through harvesting systems are increasing in the same way the autonomous systems.
A wideband piezo vibration energy harvester
8 September 2022
This paper focuses on the design of the bistable energy harvester based on a patented solution invented by the SYMME / USMB laboratory and using Amplified Piezoelectric Actuator (APA®) technology. A preliminary prototype is developed considering the lifetime and mechanical limitations. Experimental results are also given for swept sine and random vibration.
