Sputter-coating with thin layers (a few nanometers) of Pt and Au is a common preparation technique to prevent charging during SEM imaging of non-conductive materials such as wood. Disguising or hiding nanosized features in the wood surface structure is one of the main disadvantages of metal coating. On the other hand, imaging at low vacuum and low beam energy imaging are also practices commonly used for charge compensation of beam-sensitive samples, however, the resolution and signal collection are respectively compromised.
The TESCAN S8000 is fitted with BrightBeam™ UHR SEM column whose electron optics improves significantly signal collection especially at low and ultra-low beam energies in a field-free fashion, and without using sample bias. These capabilities make the new S8000 microscope an ideal instrument to observe the nanostructure of uncoated wood and wood-like specimens (such as plants, paper, and wooden fibres) and provide maximum insight.