Periodic Reporting for period 4 - smart-MEMPHIS (Smart MEMs Piezo based energy Harvesting with Integrated Supercapacitor and packaging)
Reporting period: 2017-12-15 to 2018-12-14
The performance of the system is demonstrated in two demanding applications: leadless bio-compatible cardiac pacemaker and wireless sensor networks (WSN) for structure health monitoring (SHM).
Once demonstrated for the extremely demanding pacemaker application, the same energy harvesting concept will be used also for other medical applications, as well as for various IoT devices. For example, structural health monitoring, wearable electronics and industrial wireless sensing systems need self-powered wireless nodes to operate their unique sensing application with very low maintenance. Using a modular approach, Vermon built an autonomous and wireless sensor node, including a power layer, an application and communication layers. The market for such sensing systems is substantial, and the benchmarking to competing solutions shows substantial improvement in cost, performance, power density and integration capabilities, as well as easy tailorability due to the modular structure.
In addition to the final demonstrators, several new results were obtained for component level and mass manufacturing technologies. Efficient solutions for piezoelectric interface and power management ASICs were developed by Lingköping University, supporting extraction of very small available energy (a few microwatt) from piezo-harvester. The ASICs developed demonstrated the lowest reported power consumption compared to previously known solutions. They are also energy efficient and cost-effective, have a minimal amount of off-chip components. A chip ready for production can be expected in 2-3 years.
Chalmers University developed compact and low loss supercapacitors with novel encapsulation methods. Supercapacitors are a perfect fit as an energy storage component for miniaturized self-powered systems. However, it is a challenge to fabricate miniature supercapacitors with desired performance specifically in adequate energy density and low energy loss through self-discharge and leakage current, and capacitive charging behavior at ultra-low current input. Supercapacitors with vertically aligned carbon nanotubes (VACNTs)/graphite materials construct compact and low loss supercapacitors that power miniaturized self-powered systems, or as AC line filters to replace electrolytic capacitors for systems size reduction. Also a novel encapsulation concept of supercapacitors has also been developed in the project, which promises a number of benefits such as easily adaptable form factor, surface mount and reflow soldering compatibilities. The encapsulation is based on panel level packaging methods. Fraunhofer IZM demonstrated also fan-out panel level packaging for the power management unit, ASIC combined with two capacitors in one package. The ASIC package can be soldered into any application and due to its small size can be used in several types of devices.
New methods for conceptual design of piezoelectric energy harvester were realized by RISE Acreo. The design concept allows for faster assessment of various excitation modes and harvester design after which an in-depth design can be studied. A novel multi-parameter characterization equipment for kinetic piezoelectric energy harvester was built to simultaneously measure the mechanical characteristics and study the piezo-mechanical coupling and damping mechanisms and benchmark on the accuracy of numerical simulations.
A new manufacturing process for thin PZT films was developed and subsequently taken into use at Silex's factory.
To support the mass manufacturing, both characterization and reliability assurance methods are needed. aixACCT built a full wafer poling set up, which allows to tune the PZT performance during manufacturing.
Reliability of the piezo materials and devices is still not understood thoroughly. aixACCT and Silex designed and realized an Highly Accelerated Life Time (HALT) test system which is the first one specialized for this market segment. Existing test systems are not prepared for the hysteretic behavior of the ferroelectric material as it is the case for PZT.
- A new high performance piezoelectric energy harvester for low frequencies
- A power management ASIC with the lowest reported power consumption compared to previously known solutions
- New low cost industrial process for mass manufacturing of high quality PZT thin films, with up to 10000 times longer life time of material
- New characterization and reliability assurance methods and tools for PZT thin film devices and piezoelectric energy harvesting devices
- Novel encapsulation concept of supercapacitors
- New nanomaterials for supercapacitors reaching beyond the state-of-the-art energy density and frequency response properties.