Femtosecond Laser Direct Writing of 3D Silica‐like Microstructure from Hybrid Epoxy Cyclohexyl POSS

Abstract

Given the importance of epoxy cyclohexyl polyhedral oligomeric silsesquioxane (epoxy‐POSS) as a silica‐like hybrid material of optical clarity, high thermal and mechanic stability, the two‐photon initiated polymerization of epoxy‐POSS using diphenyliodonium hexafluorophosphate as photoacid generators for UV lithography and femtosecond laser direct writing is studied. The hybrid resist exhibits high thermal stability: decomposition temperatures are found at ≈350 and 400 °C when calcined in air and argon, respectively. The corresponding calcined products are found as silica‐like structures with chemical formulas of C1.5SiO3.5 and C5SiO3, evidenced by energy dispersive X‐ray analysis (EDX), fourier‐transform infrared spectroscopy (FTIR), and elemental analysis. An equation regarding the two‐photon polymerized line width as functions of intensity of laser (Plaser) and scanning speed (V) is proposed in describing the effect of Gaussian light on polymerized lines. Experimental verification of the equation is given to prove a nonlinear optical process. Line width with a resolution of 250 nm is achieved on a glass substrate, while the resolution is 400 nm when fabricated on a silicon wafer. 3D structured woodpiles are fabricated and show no volumetric shrinkage upon 300 °C calcination in air environment, demonstrating a high thermal stability.

A sinterless, low-temperature route to 3D print nanoscale optical-grade glass

“…POSS polymers have been studied for their suitability as templating materials for semiconductors within different lithography techniques ( 36 – 38 ). More recently, epoxy-functionalized POSS resins ( 39 ) have successfully been applied in TPP printing. However, the reported efforts still focused on the synthesis of temperature-stable hybrid polymers rather than exploiting the POSS material platform as a precursor to manufacture purely inorganic materials.…”

“…However, the reported efforts still focused on the synthesis of temperature-stable hybrid polymers rather than exploiting the POSS material platform as a precursor to manufacture purely inorganic materials. Thermal decomposition of printed parts has been found to form glass ceramics with organic impurities, and no optical properties have been reported ( 39 ). Like sol-gel precursors, epoxy-functionalized resins also constrain prints because printing is performed within spin-coated gel thin films, which limits structures to low aspect ratios on flat substrates.…”

Photopatterning and Electrochemical Energy Storage Properties of an On-Chip Organic Radical Microbattery

“…Furthermore, FTIR spectroscopy of SU8 with no polymerization is measured for unreacted epoxide evaluation. α values for cross-linked SU8, e SU8, and Li + - e SU8 are then calculated as 1, 0.87, and 0.43, respectively, according to the formula used in previous literatures. , The drastic reduction in α for Li + - e SU8 containing 0.2 M LiClO 4 may be ascribed to the solvated ions in the SU8 polymer chains that can increase the physical distance between reacted epoxide groups and the energy required for crosslinking. Low α consequently results in smaller thickness of the SU8 film because monomers and oligomers may dissolve in an organic developer.…”

Hierarchical ordering in light-triggered additive manufacturing

“…87 Or can consist on a ceramic from which a glassy or metallic material can be recovered through post-printing curing. [88][89][90][91][92][93][94] ii) Hybrid polymeric materials can also refer to matrices finally containing at least two microphases of different types, as, for example, to mechanically strong fibres (such as glass fibres, carbon fibres, or nanocellulose) dispersed in a polymeric matrix, [95][96][97][98][99][100][101] or to nanocrystalline moieties covalently embedded within the final structure of the polymeric material.…”