microbatteries

Microbatteries are energy storage devices engineered at millimeter scale or smaller to power microelectronic systems. They are designed for integration with microelectromechanical systems (MEMS), micro sensors, and compact medical implants, enabling autonomous operation of miniature electronics. Microbatteries can be primary (non-rechargeable) or secondary (rechargeable). Common chemistries include thin-film lithium and lithium-ion variants, zinc-based chemistries, and solid-state configurations, often implemented as planar or three-dimensional microstructures formed by microfabrication techniques such as thin-film deposition, lithography, and electrochemical etching.

Architectures range from planar interdigitated designs to three-dimensional microtubes or interlayers that maximize electrode area within a small footprint. Solid-state electrolytes are frequently used to improve safety and enable stacking in compact packages. Fabrication approaches emphasize compatibility with semiconductor processes and low-temperature processing to enable on-chip integration.

Applications include powering MEMS sensors, wireless microdevices, medical implants, and soft robotics where space, weight, and rapid response are critical.

Performance metrics involve energy density, power density, cycle life, and safety. Compared with larger batteries, microbatteries often sacrifice energy density for higher form-factor compatibility and better integration; packaging, sealing, and thermal management are crucial at small scales.

Challenges include manufacturing cost and yield, long-term reliability under mechanical and thermal stress, and integration with other on-chip components. Ongoing research explores new chemistries, solid-state electrolytes, advanced microfabrication techniques, and hybrid energy storage concepts such as coupling microbatteries with micro-supercapacitors or energy harvesters.