By combining 3D holographic lithography and 2D photolithography, researchers from the University of Illinois at Urbana-Champaign have demonstrated a 3D microbattery suitable for large-scale on-chip integration with microelectronic devices. Applications for the holographically patterned battery include autonomous microscale actuators, distributed wireless sensors and transmitters, monitors, and portable and implantable medical devices.
To create the desired electrode shape, the researchers used 2D photolithography. 3D holographic lithography defined the interior structure of electrodes.
Enabled by the 3D holographic patterning technique — where multiple optical beams interfere inside the photoresist, creating a desirable three-dimensional structure — the battery possesses well-defined, periodically structured porous electrodes. The electrodes facilitate the fast transports of electrons and ions inside the battery.
Although accurate control on the interfering optical beams is required to construct 3D holographic lithography, recent advances have simplified the required optics, enabling creation of structures via a single incident beam and standard photoresist processing.
