Abstract

Neutral atom microscopy (NAM) is a new field that uses beams of neutral atoms to image surfaces. The first NAM instrument – the Scanning Helium Microscope (SHeM) – uses a particle beam of neutral helium atoms to form the image, rather than photons (light) or electrons. By exploiting the large scattering cross-section of helium to atomic scale surface features, coupled with its neutral/inert nature and extremely low energy (~ 60 meV), the SHeM is a uniquely sensitive imaging technology capable of visualising surfaces entirely non-destructively. The SHeM enables the study of materials (and their applications) whose visualisation is constrained, whether by intrinsic insensitivity, the requirement for surface treatments/coatings, or by surface damage altering the material under investigation. Here we present the SHeM imaging of bacterial biofilms, highlighting its sensitivity to the surface of extracellular polymeric substance matrix in the absence of contrast agents and dyes and without inducing radiative damage.