A capacitive sensing system is used to measure a timevarying ion current through a channel, such as an ion channel or protein pore. The surface emits radiation, and the first array is arranged over the surface and arranged to provide cooling to the surface, the first array including a plurality of TECs. Within the central opening is a guide tube that moves vertically and has oppositely disposed slots. By providing a data-centric device with voice capabilities there is a new range of features that allow incoming data events to trigger outgoing voice events. A closure seals the paint-carrying surface of the paint roller within the body and prevents hardening of paint on the paint-carrying surface of the paint roller.