http://www.theatlantic.com/life/archive/2011/12/the-nanomembrane-probe-brings-us-closer-to-a-cure-for-epilepsy/249334/This new device allows researchers to record brain activity over a much larger area and with higher resolution than anything previously used

Recording signals from the brain has just become a whole lot easier. And a lot more flexible.
A new, ultra-thin device capable of recording brain activity without having to use penetrating electrodes could potentially allow researchers to learn information about the brain's electrical activity without invasive implants.
The device is comprised of 720 silicon nanomembrane transistors in an array consisting of 360 different channels. The silicon enables it to be more flexible and foldable than a conventional rigid electrode array. This means it can be placed not only on the brain surface, but inside the grooves or sulci and the deeper fissures as well as between the brain's hemispheres.
The array eliminates the requirement for each sensor to have its own separate wire. This arrangement allows the device to cover a much larger brain area with higher resolution than standard electrode arrays currently used by neuroscience laboratories around the world.