A Monolithic Micro-Tensile Tester for Investigating Silicon Dioxide Polymorph Micromechanics, Fabricated and Operated Using a Femtosecond Laser

Abstract

Mechanical testing of materials at the microscales is challenging. It requires delicate procedures not only for producing and handling the specimen to be tested, but also for applying an accurate and controlled force. This endeavor is even more challenging when it comes to investigating the behavior of brittle materials such as glass. Here, we present a microtensile tester for investigating silica glass polymorphs. The instrument is entirely made of silica and for which the same femtosecond laser is not only used for fabricating the device, but also for operating it (loading the specimen) as well as for performing in situ measurements. As a proof-of-concept, we present a stress-strain curve of fused silica for unprecedented high tensile stress of 2.4 GPa, as well as preliminary results of the elastic modulus of femtosecond laser-affected zones of fused silica, providing new insights on their microstructures and mechanical behavior.

Elastic properties of self-organized nanogratings produced by femtosecond laser exposure of fused silica

“…Therefore, by modifying the constitutive material of a vibrating structure using laser irradiation a noticeable frequency shift of its resonance is expected, as a change in Young's modulus and mass distribution occurs Ref. [18,28]. Here, we use this principle to evaluate the local change of Young's modulus.…”

“…For this case, E l,t decays from 50 GPa to 35 GPa, going from lower to higher deposited energies. Athanasiou and Bellouard [18] made an estimate, by indirect means of the transverse Young's modulus with similar exposure conditions-a polarization of 90 • , pulse energy ∼210 nJ, and deposited energy ∼20 J/mm 2 . They report a significant decrease of the elastic constant, with an estimated value of ∼30 GPa.…”

“…The exact mechanism leading to the creation of these nanofeatures [2,[10][11][12][13] is to date not established. Nonetheless, this type of modification has been used in various photonics applications, such as polarization converters [14] or optical memory devices [15], but also for controlling the stress state in materials [16,17], inducing controlled displacements [18][19][20], or for tuning properties, such as the coefficient of thermal expansion [21]. To date, these changes of thermomechanical behavior cannot be fully understood, predicted, and controlled without a deeper * pieter.vlugter@epfl.ch understanding of the mechanical properties of the nanogratings.…”

Hybrid Nanosecond Laser Processing and Heat Treatment for Rapid Preparation of Super-Hydrophobic Copper Surface

“…In addition, etching reagents are mostly corrosive reagents with safety and environmental issues. Unlike the above methods, lasers can fabricate and precisely control the size of micro/nano-structures [18][19][20][21][22][23]. Therefore, laser processing can be used to quickly obtain micro/nano-structures.…”

Synthesis and Deposition of Ag Nanoparticles by Combining Laser Ablation and Electrophoretic Deposition Techniques

“…Coatings 2019, 9, 571 2 of 9 A wide range of techniques for producing nanoparticles is used in the literature, and can be roughly classified into two groups based on chemical or physical processes. The most popular method is chemical reduction, whereby organic or inorganic agents are used to reduce Ag salt and generate nanoparticles with different sizes, shapes, and composition [15][16][17][18][19]. Most of these methods use chemical reactants, surfactants, or stabilizers which contaminate the final nanoparticles, necessitating further extraction and purification [17].…”