Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - ENHANCE (Piezoelectric Energy Harvesters for Self-Powered Automotive Sensors: from Advanced Lead-Free Materials to Smart Systems)

Teaser

Each new generation of cars usually offers additional functionalities, more sophisticated sensing (> 100 sensors) and communication systems. At present, car industry is desperately trying to reduce the total weight of cars and consumption, particularly of fuel in order to...

Summary

Each new generation of cars usually offers additional functionalities, more sophisticated sensing (> 100 sensors) and communication systems. At present, car industry is desperately trying to reduce the total weight of cars and consumption, particularly of fuel in order to reduce the CO2 emission. For example, the decrease of car weight by 100 kg drops the CO2 emission by 4-6 g/km. The signal transfer and supply of the high number of sensors in a vehicle introduce a complex network of wires, which has quite an impact on the mass of vehicles (up to 50 kg, several km in length) and add complexity and costs to installation and maintenance diagnostics. Thus, simplification and miniaturization of these networks by using self-powered wireless sensors drawing the source of power from the environment are highly demanded for inaccessible locations or corrosive /harsh working conditions.
The main purpose of the ENHANCE project is to create a multidisciplinary joint research activity, implying chemistry, materials science, physics, mechanics, engineering and electronics (Fig. 1), and which will be considerably more efficient than the uncoordinated efforts of individual partners in bypassing the present limitations to enable harvesters with high-power density and their systems offering stabilized output voltage in 1-3 V range and adapted to specific needs of sensors with high autonomy and working in temperature ranges from room temperature to 600 °C in vehicles. We propose to develop hybrid scavenging of energies available in the cars (heat (Th)– light (Lt) - vibrations (Vi)) and/or to use multiple conversion effects (piezoelectric (Pi) - pyroelectric (Py) – electromagnetic (EM) – photovoltaic (PV)) by the same transducer - heterostructure based on piezoelectric/ferroelectric/multiferroic crystals, films or nanostructures in line with the final goals of the project – creation of the efficient energy scavengers and with reasonable price and viable technologies of fabrication and integration for real industrial applications to stimulate the integration of newly developed products and technologies by the industry.

Work performed

\"On the front of the comprehension of what applications the industry is currently investing on, the development of devices and materials viable for the technology transfer all ESRs have been involved through secondment periods at the premises of the Industrial Partners, Academic partners and literature review all focusing on several technical aspects ranging from materials to devices.
The optimisation of growth processes of different potential lead-free materials and their physical properties is considered by chemical methods such as CVD, spray pyrolysis, and electrospinning techniques: i) films and vertically aligned nanostructures of BiFeO3, LiNbO3, and K1-xNaxNbO3,ii) self-supported nanomeshes (Fig. 2). The design/control of the deposited coatings are supported by synthesis and physico-chemical/mechanistic studies of precursors and modelling/simulation of chemical processes. To study the direct piezoelectric constants, a novel methodology named ‘Direct Piezoelectric Force Microscopy’ has been employed. Optimized design of piezoelectric transducers and nanogenerators have been reviewed. Energy harvesting of 9.62 mW cm-3 power density by using LiNbO3/Si structure vibrating at 1.14 kHz was demonstrated and integrated with sensor node (Fig. 3). This opens promising outcomes for lead-free energy harvesting solutions and their fast implementation. Different modes of scavenging and architectures for adaptation of an Amplified Piezo Actuators (APAs®) were considered. The combination on the Pi-EM conversion effects by further developing of SSHI interface allowed to demonstrate a global converted energy gain of 40%. The design and fabrication of hybrid Pi-Py EH able to operate at constant temperature is in progress. Wireless electromagnetic energy transfer from the harvester to the sensor, and fabrication of the complete systems including nonlinear and bistability configurations in order to validate the stable targeted output supply in real-world applications is considered, as well.
The ENHANCE network is committed to prepare the ESRs to their future career. The main training categories on which the network focuses span from practical research skills to broad- based multidisciplinary training; commercial and other transferable skills will give the researchers a solid knowledge base to be leveraged in both the academic and non-academic environment. The Consortium provides, either locally or at a network level, the trainings by means of lectures, seminars, summer schools, workshops and online e-learning, and web-based tools.
Three training schools open to external participants were organized by the ENHANCE network: \"\"Introductory School\"\", \"\"Career Opportunities\"\", and \"\"Molecular engineering and advanced materials\"\". The lectures held during the Network’s training events have been live-streamed, and when made available online (on YouTube channel “ITN-ENHANCE Project” & www.itn-enhance.com).\"

Final results

ENHANCE is primarily designed to maximise the formal training opportunities, knowledge-sharing and professional development of the ESRs, but also offers benefits to the scientific staff at the host institutions, to their associated partners and to the EU public. We intend to meet EU policy aims and help to maintain EU competitiveness - both in the training of researchers and in the development of cutting-edge technology - in the face of increasing competition from overseas nations. To summarize so far ENHANCE progress beyond the state of the art: advanced metalorganic precursors of alkaline elements, growth of controlled piezoelectric films and nanomeshes, implementation of highly efficient lead-free materials for energy harvesting, advanced nonlinear interfaces, and efficient wireless power transfer.
A key strength of ENHANCE is that ESRs are trained through the entire research process, from theory to commercial exploitation, regardless of the focus of their individual research topic. ENHANCE promotes the acquisition of key skills needed by ESRs for their future careers in either the public or the private sectors and to improve the career prospects and employability of ESRs and stimulates a creative approach to scientific problem- solving by applying techniques from different fields. ENHANCE also includes opportunities for all academic and industrial participants to use their enhanced understanding of novel multifunctional materials to propose new or improved device concepts and designs for energy harvesting, to benefit from the exchange of students and of technical knowledge, and to establish also long-term collaborations (larger projects) and transfer of knowledge.
ENHANCE initiates a synergy and consolidates an EU scientific communities in the fields of advanced piezoelectric materials and energy harvesting in automotive/aerospace sensors to increase the worldwide competence of the EU in both academia and the private sector. ENHANCE will pave the way to an European commercial activity for versatile harvesting solutions, adapted for car/aerospace industry will have also an indirect impact on the competitiveness of European SMEs outside of the partnership, as numerous fields of activity addressed by ENHANCE are representative of SMEs’ sectors. Consequently, this ITN will increase the competitiveness of a wide range of European SMEs.

Website & more info

More info: http://www.itn-enhance.com.