Periodic Reporting for period 3 - MetaVEH (Metamaterial Enabled Vibration Energy Harvesting)
Período documentado: 2023-07-01 hasta 2025-07-31
Modern societies depend on millions of sensors to monitor bridges, machinery, transport systems, and the environment. Most of them rely on batteries that must be replaced regularly, causing cost, labour, and electronic waste. The MetaVEH project tackled this challenge by developing self-powered, lead-free vibration energy harvesters that generate electricity for wireless sensors using only ambient vibrations.
At the heart of the project lies a new class of metamaterial-enhanced mechanical structures—engineered materials that control how vibrations propagate. By carefully grading their geometry, MetaVEH devices can trap and amplify vibrations over a wide frequency range, allowing much more energy to be harvested than with conventional systems.
The project also developed advanced electronic interfaces to efficiently convert this mechanical energy into stable electrical power. A key breakthrough was the self-powered synchronized charge extraction (SP-SECE) circuit, which operates without batteries or external control. Combined with ultra-low-power microcontrollers and wireless modules, it enables fully autonomous sensors transmitting data via Bluetooth or LoRa networks.
Several prototypes were designed, fabricated, and tested at laboratory scale. The final demonstrator—EMetaNode—proved capable of powering sensors continuously for several days using only environmental vibrations, integrating harvesting, data processing, and wireless communication in a single compact platform.
By eliminating batteries, MetaVEH reduces environmental impact and maintenance costs, enabling long-term monitoring of critical infrastructure and remote environments. The project directly supports the EU’s goals for clean energy (SDG 7), industry and innovation (SDG 9), and climate action (SDG 13).
Beyond the main harvester, MetaVEH produced several complementary innovations: 3D-printed lead-free piezoelectric materials (KNN) for sustainable micro-devices; Magnetic frequency-upconversion modules extending the operational bandwidth; Contact-based meta-actuators for energy-efficient motion and vibration control.
These outcomes open new opportunities for autonomous sensing, soft robotics, and green electronics. The project reached TRL 4 and established a clear roadmap for industrial implementation through future EIC Transition and Innosuisse initiatives.
At the heart of the project lies a new class of metamaterial-enhanced mechanical structures—engineered materials that control how vibrations propagate. By carefully grading their geometry, MetaVEH devices can trap and amplify vibrations over a wide frequency range, allowing much more energy to be harvested than with conventional systems.
The project also developed advanced electronic interfaces to efficiently convert this mechanical energy into stable electrical power. A key breakthrough was the self-powered synchronized charge extraction (SP-SECE) circuit, which operates without batteries or external control. Combined with ultra-low-power microcontrollers and wireless modules, it enables fully autonomous sensors transmitting data via Bluetooth or LoRa networks.
Several prototypes were designed, fabricated, and tested at laboratory scale. The final demonstrator—EMetaNode—proved capable of powering sensors continuously for several days using only environmental vibrations, integrating harvesting, data processing, and wireless communication in a single compact platform.
By eliminating batteries, MetaVEH reduces environmental impact and maintenance costs, enabling long-term monitoring of critical infrastructure and remote environments. The project directly supports the EU’s goals for clean energy (SDG 7), industry and innovation (SDG 9), and climate action (SDG 13).
Beyond the main harvester, MetaVEH produced several complementary innovations: 3D-printed lead-free piezoelectric materials (KNN) for sustainable micro-devices; Magnetic frequency-upconversion modules extending the operational bandwidth; Contact-based meta-actuators for energy-efficient motion and vibration control.
These outcomes open new opportunities for autonomous sensing, soft robotics, and green electronics. The project reached TRL 4 and established a clear roadmap for industrial implementation through future EIC Transition and Innosuisse initiatives.
During the final phase, work advanced successfully across all technical and management work packages, culminating in the full demonstration of the MetaVEH concept — autonomous, lead-free vibration energy harvesters enhanced by metamaterial architectures and nonlinear circuits. Despite early pandemic challenges, coordination remained strong, leading to validated prototypes at both macro and micro scales.
WP1–WP2 (Coordination, Dissemination, and Management):
Project management continued smoothly after coordination transferred from ETH Zürich to ZHAW. The project website (www.metaveh.com) was regularly updated with publications and outreach materials. Dissemination was extensive: over 25 journal papers, 30+ conference presentations, and two international workshops (BOHEME–METAVEH 2023 and Euromech 649, London 2024). Outreach included Il Sole 24 Ore, the Waves – Dive In! exhibition at ETH Zürich, and Open Days at Politecnico di Milano.
WP3 (Mathematical and Numerical Tools):
New modelling and simulation frameworks were developed for graded and nonlinear metamaterials, combining Bloch–Floquet theory and nonlinear dynamics. These models guided the design of both macro- and micro-scale prototypes and enabled prediction of broadband energy-harvesting behaviour.
WP4 (Macrofabrication):
Binder-jetting 3D printing and laser micro-machining produced complex lead-free piezoelectric metastructures (KNN) and diode-less rectifiers capable of broadband energy collection. Laboratory tests at ETH and ZHAW validated wideband performance (5–500 Hz) and led to the creation of the EMetaNode prototype — a compact autonomous harvester integrating mechanical, electronic, and wireless subsystems.
WP5 (MEMS Meta-harvester Fabrication):
MEMS prototypes based on AlN and AlScN thin films achieved high-Q resonant modes, enabling both micro-harvesting and RF filtering. A novel on-chip characterisation method for piezoelectric properties was demonstrated, improving MEMS design efficiency.
WP6 (Testing and Benchmarking):
A new dynamic test bench simulated infinite waveguides under realistic vibration conditions. Testing of nonlinear and contact-based harvesters confirmed that the EMetaNode can power IoT sensors for several days from ambient vibrations, achieving TRL 5.
WP7 (Integration and Exploitation):
The final integration combined low-power firmware (written in Rust) with LoRa-based data transmission and cloud connectivity. Deliverables D7.1–D7.2 defined the marketing and business plan and engaged industrial partners (Multiwave, Kistler, Irmos) through Letters of Intent and pilot assessments.
The Innovation Radar exercise (June 2025) identified six key innovations, including three flagship results:
Portable vibration energy harvesters for space- and time-sparse sensing (EMetaNode);
Contact-based meta-actuators for adaptive vibration control;
Magnetic frequency up-conversion for broadband harvesting.
Overall, MetaVEH achieved all its objectives, moving from concept (TRL 2–3) to validated prototypes (TRL 5). The project proved that sustainable materials, metamaterial design, and efficient electronics can converge into a single, battery-free platform — a key step toward self-powered smart infrastructure and IoT systems.
WP1–WP2 (Coordination, Dissemination, and Management):
Project management continued smoothly after coordination transferred from ETH Zürich to ZHAW. The project website (www.metaveh.com) was regularly updated with publications and outreach materials. Dissemination was extensive: over 25 journal papers, 30+ conference presentations, and two international workshops (BOHEME–METAVEH 2023 and Euromech 649, London 2024). Outreach included Il Sole 24 Ore, the Waves – Dive In! exhibition at ETH Zürich, and Open Days at Politecnico di Milano.
WP3 (Mathematical and Numerical Tools):
New modelling and simulation frameworks were developed for graded and nonlinear metamaterials, combining Bloch–Floquet theory and nonlinear dynamics. These models guided the design of both macro- and micro-scale prototypes and enabled prediction of broadband energy-harvesting behaviour.
WP4 (Macrofabrication):
Binder-jetting 3D printing and laser micro-machining produced complex lead-free piezoelectric metastructures (KNN) and diode-less rectifiers capable of broadband energy collection. Laboratory tests at ETH and ZHAW validated wideband performance (5–500 Hz) and led to the creation of the EMetaNode prototype — a compact autonomous harvester integrating mechanical, electronic, and wireless subsystems.
WP5 (MEMS Meta-harvester Fabrication):
MEMS prototypes based on AlN and AlScN thin films achieved high-Q resonant modes, enabling both micro-harvesting and RF filtering. A novel on-chip characterisation method for piezoelectric properties was demonstrated, improving MEMS design efficiency.
WP6 (Testing and Benchmarking):
A new dynamic test bench simulated infinite waveguides under realistic vibration conditions. Testing of nonlinear and contact-based harvesters confirmed that the EMetaNode can power IoT sensors for several days from ambient vibrations, achieving TRL 5.
WP7 (Integration and Exploitation):
The final integration combined low-power firmware (written in Rust) with LoRa-based data transmission and cloud connectivity. Deliverables D7.1–D7.2 defined the marketing and business plan and engaged industrial partners (Multiwave, Kistler, Irmos) through Letters of Intent and pilot assessments.
The Innovation Radar exercise (June 2025) identified six key innovations, including three flagship results:
Portable vibration energy harvesters for space- and time-sparse sensing (EMetaNode);
Contact-based meta-actuators for adaptive vibration control;
Magnetic frequency up-conversion for broadband harvesting.
Overall, MetaVEH achieved all its objectives, moving from concept (TRL 2–3) to validated prototypes (TRL 5). The project proved that sustainable materials, metamaterial design, and efficient electronics can converge into a single, battery-free platform — a key step toward self-powered smart infrastructure and IoT systems.
This research project is motivated by the exponential growth of the wireless sensors market, hence the active involvement of Assimilate, an emerging technologies SME, ST Microelectronics, world leader in MEMS fabrication, in this project, and the need to probe key physical parameters (motion and acceleration, temperature, chemical markers amongst others) for sensors that must be powered without human intervention; furthermore in sensors there is a drive for green sustainable chemistry and thereby to avoid solar panels containing rare metals and toxic materials (e.g. Lead, Cadmium), and ultimately, to remove the need for batteries. The achievement of such a result is enabled by the continuous reduction of the energy demand of sensors. Today, it is possible to purchase MEMS for sensing inertial quantities (acceleration and/or angular velocity) that need less than 10 μW to stay in the idle condition; measurements can be done in ultra-low power mode, asking for an average of 20-40 μW and peaks around 200 μW. Moreover, the technology roadmaps of microelectronics foresee that power consumption will decrease to tens of nanowatts and below in the next future. The applications include, for instance, structural health monitoring (SHM) devices used in civil engineering, sensors used in the aerospace and automotive industries, geophysical networks located around faults, volcanoes and coastal areas and for space exploration. Many of these sensors are integrated in early warning systems, and their deployment and operational stability are critical for the safety and the resilience of modern society, transport systems and scientific missions.