Hyman professor of chemistry Charles Lieber has created a transistor so small it can be used to penetrate cell membranes and probe their interiors, without disrupting function. The transistor (yellow) sits near the bend in a hairpin-shaped, lipid-coated silicon nanowire. Its scale is similar to that of intra-cellular structures such as organelles (pink and blue orbs) and actin filaments (pink strand).
Source:
https://www.harvardmagazine.com/2011/01/virus-sized-transistors.
University, Magazine.