Chapters authored
Interdigitated MEMS Supercapacitor for Powering Heart Pacemaker
Power MEMS can be defined as microelectromechanical systems for power generation and energy conversion. Energy harvesting has become an increasingly popular option for powering electronic devices as a long-lasting power source. Energy scavenging is defined as the process by which the energy is derived such as vibration, solar, wind, and thermal. Energy harvesting from the environment can prolong the life cycle and reduce the maintenance costs of electronic devices. Among the various sources of energy storage, Among the various of energy storage, supercapacitor has recently gained much interest in fields such as bioMEMS, biomedical implants and power electronic devices due to its advantages such as high power density, rapid charge and discharge and unlimited number of recharge cycles. In biomedical and bioMEMS systems, an energy storage device is needed to power other active biomedical devices within the system. For implantable devices such as a heart pacemaker, the power requirement is in the range of 30–100 μW. Microsupercapacitors play an important role in energy harvesting system, such as collecting energy from ambient energy sources. Human body is very resourceful in generating micropower in the form of heat dissipation, deformation of elastic tissue, and motion. Due to the advantages of MEMS energy harvesting system, the system can be use widely for biomedical implant devices, such as heart pacemakers and hearing aids, and can be used for a long time and without the need for battery replacement. In this work, planar and double-stacked interdigital electrode supercapacitor designs were modeled using Coventorware software. From simulation, it is observed that for planar structure, the specific capacitance is 0.22 mF/cm−2, and for double-stacked structure specific capacitance can be increased to 0.48 mF/cm−2. In terms of specific power, the planar structure produces 0.99 mW/cm−2, and the double-stacked structure produces 2.18 mW/cm−2. These results highlight the superiority of the double-stacked MEMS interdigital supercapacitor design compared with its planar counterpart in terms of charging capacity and electrical performance, thus making it favorable for powering heart pacemaker.
Part of the book: Supercapacitor Design and Applications