Mechanical Properties of 3D Nanostructures Obtained by Focused Electron/Ion Beam-Induced Deposition: A Review

Abstract

This article reviews the state-of-the -art of mechanical material properties and measurement methods of nanostructures obtained by two nanoscale additive manufacturing methods: gas-assisted focused electron and focused ion beam-induced deposition using volatile organic and organometallic precursors. Gas-assisted focused electron and ion beam-induced deposition-based additive manufacturing technologies enable the direct-write fabrication of complex 3D nanostructures with feature dimensions below 50 nm, pore-free and nanometer-smooth high-fidelity surfaces, and an increasing flexibility in choice of materials via novel precursors. We discuss the principles, possibilities, and literature proven examples related to the mechanical properties of such 3D nanoobjects. Most materials fabricated via these approaches reveal a metal matrix composition with metallic nanograins embedded in a carbonaceous matrix. By that, specific material functionalities, such as magnetic, electrical, or optical can be largely independently tuned with respect to mechanical properties governed mostly by the matrix. The carbonaceous matrix can be precisely tuned via electron and/or ion beam irradiation with respect to the carbon network, carbon hybridization, and volatile element content and thus take mechanical properties ranging from polymeric-like over amorphous-like toward diamond-like behavior. Such metal matrix nanostructures open up entirely new applications, which exploit their full potential in combination with the unique 3D additive manufacturing capabilities at the nanoscale.

Focused Electron Beam-Based 3D Nanoprinting for Scanning Probe Microscopy: A Review

“…During AFM operation, the tip experiences forces in vertical and lateral directions, which immediately implies mechanical properties of single pillars, which can be considered as fundamental building blocks for more complex 3D-FEBID architectures. This topic is reviewed in great detail by Utke et al in another article of this special issue, which gives a comprehensive insight into mechanical properties, and their dependency on fabrication and on post-growth treatment approaches [92]. In brief, FEBID pillars are much stiffer along the main axis compared to situations where lateral forces become relevant [66].…”

“…EBC has been demonstrated to change the Young modulus from about 14 GPa to 80 GPa (even higher values are possible [92]), without affecting the overall morphology, including the apex radii [21]. The great advantage of EBC is the minimally disruptive influence, even on fragile 3D nanostructures, which makes this approach almost straightforward.…”

Focused Ion Beam Processing for 3D Chiral Photonics Nanostructures

“…The first approaches of controlled focused ion/electron beam induced deposition (FIBID/FEBID) growth were investigated in [ 17 , 36 , 52 , 53 ], paving the way to the micro/nanofabrication of precise and complex-shaped 3D structures. Today, the availability of different gas precursors [ 36 ] to be used in conjunction with the beam is enabling a wide gamut of optical, magnetic, superconducting, and mechanical properties [ 52 , 54 , 55 , 56 ].…”

Quantitative mechanics of 3D printed nanopillars interacting with bacterial cells

“…Currently, however, the mechanical characterization of single EBID nanostructures is challenging and requires complex instrumentation consisting of advanced mechanical testing machines (e.g., AFM or nanoindenters) mounted inside SEM chambers. Some studies [39][40][41][42] have investigated the mechanical behavior of EBID-made nanostructures by using this combination of instruments. For instance, Friedli et al 39 have applied bending tests using an AFM tip installed inside an SEM machine to determine the force constant and the resonance frequency of high aspect ratio vertical nanopillars grown by EBID from the organometallic precursor Cu (C 5 HF 6 O 2 ) 2 •xH 2 O.…”

“…The fracture stress of nanopillars deposited by EBID has, however, not been previously measured. Utke et al 42 measured the fracture stress on large volume structures deposited using Co 2 (CO) 8 and Au(tfac)Me 2 as precursors. Reiser et al 44 measured the stress at 7% strain of micro and nanopillars using nanoindentation and micro-compression, but not the fracture stress.…”