Direct printing of functional 3D objects using polymerization-induced phase separation

Abstract

Abstract3D printing has enabled materials, geometries and functional properties to be combined in unique ways otherwise unattainable via traditional manufacturing techniques, yet its adoption as a mainstream manufacturing platform for functional objects is hindered by the physical challenges in printing multiple materials. Vat polymerization offers a polymer chemistry-based approach to generating smart objects, in which phase separation is used to control the spatial positioning of materials and thus at once, achieve desirable morphological and functional properties of final 3D printed objects. This study demonstrates how the spatial distribution of different material phases can be modulated by controlling the kinetics of gelation, cross-linking density and material diffusivity through the judicious selection of photoresin components. A continuum of morphologies, ranging from functional coatings, gradients and composites are generated, enabling the fabrication of 3D piezoresistive sensors, 5G antennas and antimicrobial objects and thus illustrating a promising way forward in the integration of dissimilar materials in 3D printing of smart or functional parts.

Superhydrophobic Polymer Composite Surfaces Developed via Photopolymerization

“…Besides pattern generation, photopolymerization also induces phase separation of NPs toward the surface. This phenomenon has previously been reported using silicon NPs, 25 semiconductor nanocrystals, 28 silver decanoate, 29 silica NPs, 30 polymer blends, 31 − 33 and polymer–solvent systems. 9 , 15 Figure 1 b also shows a magnified view of a single bump, indicating the expected outward movement of NPs from the polymer-rich regions to monomer-rich regions (namely upward to the surface) owing to PIPS, which is key to good surface coverage.…”

Facile fabrication of micro-/nanostructured, superhydrophobic membranes with adjustable porosity by 3D printing

“…20,[39][40][41][42] As of late, it has been effectively applied in the fabrication of micro/-nanoporous materials, such as glass and polymers, using SLA. [43][44][45][46][47] In this paper, we report the SLA 3D printing of thin superhydrophobic membranes (100-400 mm) with adjustable porosity in the submicron range with 30 nm to 300 nm pores. The process combines both, required topography and surface chemistry for achieving superhydrophobicity in a single step.…”

UV‐Sinterable Silver Oxalate‐Based Molecular Inks and Their Application for In‐Mold Electronics

“…IME technology is anticipated to be a game changer in the production of 3D human‐machine interfaces (HMIs) for consumer electronics, home appliances, automotive and aerospace applications ( Figure a,b). The potential of producing 3D electronic devices directly from multi‐material 3D printing is in its infancy and promises to take shape in the future, [ 23 ] but from today's manufacturing perspective IME is interesting because it utilizes traditional, high volume processes to print functional inks on flat, 2D substrates which are thermoformed into 3D shapes and subsequently injection molded to produce a functional, lightweight and lower cost part or device (Figure 1c–e). However, in the transition from 2D to 3D during thermoforming, the traces must undergo elongation and strain at temperatures above the glass transition temperature of the substrates and remain conductive after the part is shaped and cooled.…”