Energy harvesting devices and their unique ability to convert the ambient energy into electrical energy has attracted much interest in industrial and manufacturing sectors. Vibration is one of the common sources in energy harvesting and a widely used method of converting vibration into the electricity is by using the piezoelectric materials. One important application of such piezoelectric devices is conversion of heartbeat vibrations to electrical energy needed for powering batteries of leadless pacemakers. If enough electricity is generated, the pacemaker operates without having a battery and the patient does not need to have a surgery every seven to ten years to have the battery replaced. Despite their attractiveness for lack of leads and eliminating the need for an open surgery for implantation, because of power requirements large battery size has been an issue that hindered the development of leadless pacemakers for 20 years. Improved leadless pacemaker design and technologies can result in important impact on Implantable Cardiac Pacemaker Market that is estimated to be of ~$1.84B in size of revenues in U.S. and Western Europe combined.
Piezoelectric Energy Harvesting from Heartbeat Vibrations for MRI Compatible Leadless Pacemakers
Interdisciplinary research carried out between Aerospace Engineering and Division of Pediatric Cardiology at the University of Michigan has allowed the design of a high-output leadless pacemaker device for energy harvesting from heartbeat vibrations. The proposed device consists of several biomorph piezoelectric beams stacked on top of each other. These bimorph beams are connected to each other by high-density rigid links made of platinum. Along with utilization of tip mass and the link masses, the fan-fold geometry of the energy harvester design is small in size (1 cc in volume) and effective in reducing the natural frequency of the device to 22Hz. Proven by experiments, the proposed device generates more than 20휇푊 of power; on an order of magnitude more power than the nominal power needed for a leadless pacemaker. Moreover, the proposed device does not incorporate magnets and is thus Magnetic resonance imaging (MRI) compatible. Although the device is a linear energy harvester, it is shown that the device is relatively insensitive to heartrate. As a result, the proposed energy harvesting device has important potential to make leadless pacemakers realizable.
- Leadless cardiac pacemakers
- Large scale application has potential to replace battery in portable devices
- Generates an order of magnitude more power than the nominal power needed for a leadless pacemaker
- Small size
- MRI compatible
- Insensitive to heartrate