Figure 1. Detecting nanoscale dynamics with a SEM.

(a) Schematic of the experimental set-up. The nanowire is mounted onto the three-dimensional-positioning platform of a commercial SEM, which includes an electron gun delivering a stable collimated flux of electrons, and a SEs detector (Everhart–Thornley Detector (ETD)), whose output is used for both imaging the nanowire and measuring its dynamical motion around its equilibrium position. (b) Using Secondary Emission for nanomechanical motion detection. The very high contrast of SEM imaging (illustrated here with a 20 nm gold nanowire, scale bar, 200 nm) results in a highly peaked evolution of the SE rate as a function of the transverse displacement. The nanomechanical motion δx around its equilibrium position x₀ is therefore transduced into large variation of the SE emission rate.