Miniaturization of electronic components is now reaching the level of whole instruments, and not just parts like transistors. Thomas George recently reported on a tiny electron microscope column a “few millimeters thick and about a centimeter square”, which would work in air. The secret being an electron- transparent membrane sealing in the column's vacuum. This is exciting news for folks working in areas such as acarid chaetotaxy that would benefit from a pocket-size electron microscope. However, it's limited by a micrometer-scale resolution limit.

Help is on the way, however. In separate reports in Applied Physics Letters, Driskill-Smith et al at. published “The 'nano-triode:’ A nanoscale field-emission tube”, and Dean and Chalamala published “The environmental stability of field emission from single-walled carbon nanotubes.“

Since, as everyone knows, an electron microscope's electron gun is a triode vacuum tube, the application is obvious. Everyone old enough to remember vacuum tubes, I should say.