Highly Expandable Foam for Lithographic 3D Printing

Abstract

In modern manufacturing, it is a widely accepted limitation that the parts patterned by an additive or subtractive manufacturing process (i.e., a lathe, mill, or 3D printer) must be smaller than the machine itself that produced them. Once such parts are manufactured, they can be postprocessed, fastened together, welded, or adhesively bonded to form larger structures. We have developed a foaming prepolymer resin for lithographic additive manufacturing, which can be expanded after printing to produce parts up to 40× larger than their original volume. This allows for the fabrication of structures significantly larger than the build volume of the 3D printer that produced them. Complex geometries comprised of porous foams have implications in technologically demanding fields such as architecture, aerospace, energy, and biomedicine. This manuscript presents a comprehensive screening process for resin formulations, detailed analysis of printing parameters, and observed mechanical properties of the 3D-printed foams.

Navigation of a magnetic micro-robot through a cerebral aneurysm phantom with magnetic particle imaging

“…To achieve complete aneurysm occlusion in this case, several microrobots would have to be used and ideally functional coating material should be applied. The use of a coating 39 or 3D-printing material 40 that swells in liquid surrounding could be an option or a thrombogenic coating of the micro-robot could be an approach to improve the embolization effect. The feasibility of the micro-robot to conduct hyperthermia opens the opportunity to apply heat to the surrounding of the micro-robot as soon as it has reached the aneurysm to induce blood coagulation faster 41 .…”

Considerations Using Additive Manufacture of Emulsion Inks to Produce Respiratory Protective Filters Against Viral Respiratory Tract Infections Such as the COVID-19 Virus

“…Air bubbles can be used as a porogen, either by directly printing a UV curable foamed monomer[ 117 ] or using a foam that sets by thermogelation after it has been printed[ 118 ]. Alternatively, a blowing agent can be used within the 3D-printed part, which is decomposed post-processing to expand it into a porous material[ 119 ]. Furthermore, particles such as sieved salt can be used as a sacrificial template for a monomer to cross-link around, 75 μm extra fine salt crystals can be combined with a DLP printer and photocurable ink, although the samples had limited interconnectivity[ 120 ].…”

Self-foaming polymers: Opportunities for the next generation of personal protective equipment

“…Organic carbonates -simply referred to as "carbonates" in this revieware known for their ability to thermally decompose into CO2, as well as an alkene and an alcohol whose structures are dependent on the alkyl substituents of the carbonate (Figure 3.2). [149] For instance, di-tert-butyldicarbonate, Boc2O, is known as an exogeneous chemical blowing agent that is thermally decomposed into CO2, isobutene and tert-butanol [150]. However, its vaporization is sometimes observed before its thermolysis causing a serious safety issue because gaseous Boc2O is highly toxic.…”