EEG Series Thin-Film Grids
Thin-film polyimide arrays that record from the skull surface with no craniotomy, trading spatial resolution for a preparation that survives months.
What removing the craniotomy changes
An EEG array records from the outside of the skull. No bone is removed, the dura is never opened, and the cortex is never exposed — which removes most of the surgical risk and most of the chronic failure modes that follow it. Recordings have been held over months.
What it costs is spatial resolution. Skull and scalp spread the signal, so an EEG array measures rhythms and state rather than local circuit activity. In this work coverage and implant survival matter more than resolution, which is the opposite of the trade a penetrating array makes.
Where the difficulty moves
It moves to alignment and fixation. Designs are dimensioned from bregma, so placement is the experiment: a design laid out for mouse cortex put on a rat skull samples different structures. A drop of water is enough to adhere an array to the skull; the array conforms and surface tension holds it while the fixation cures.
Specifications
12 µm polyimide, 500 µm platinum disc sites, 3 to 32 sites, cables of 7, 8 and 10 mm. Catalog designs cover mice and rats. Packages H16/HC16/HZ16/X3-H16 and H32/HC32/HZ32/X3-H32.
Typical work
Sleep and wake staging, seizure detection, cortical rhythms, and long-duration monitoring.
Research use only.