Designing a 3-D printed structure is hard enough when the product is inches or feet in size. Imagine shrinking it smaller than a drop of water, smaller even than a human hair, until it is dwarfed by a common bacterium.
This impossibly small structure can be made a reality with focused electron beam induced deposition, or FEBID, to essentially 3-D print at the nanoscale. FEBID uses an electron beam from a scanning electron microscope to condense gaseous precursor molecules into a solid deposit on a surface.
Previously, this method was laborious, prone to errors and impractical for creating complex structures larger than a few nanometers. Now, a team at the Department of Energy’s Oak Ridge National Laboratory, in collaboration with the University of Tennessee and the Graz University of Technology, has developed a powerful simulation-guided drafting process to improve FEBID and introduce new possibilities in nanomanufacturing.
The new system integrates design and construction into one streamlined process that creates complex 3-D nanostructures.
The ability to accurately design custom nanostructures opens up a host of novel applications in 3-D plasmonics, free-standing nano-sensors and nano-mechanical elements on the lower nanoscale which are almost impossible to fabricate by other techniques.
The process uses a 3-D simulation to guide the electron beam and replicate complex lattices and meshes between 10 nanometers and one micron in size. The model tracks electron scattering paths and the release of secondary electrons to predict the pattern of deposition on the surface of the material and visualize the final structure of an experiment.
The innovative aspect of this work, is the convergence of experiments and simulation. The simulation guides the experimental construction, while the completed experiments, in turn, provide feedback on the accuracy and strength of the simulation. Designs are fed into the simulation and drafting program, and any inconsistencies between the two caused by secondary electron activity can be caught before the experiment.
