Oxygen-Permeable Films for Continuous Additive, Subtractive, and Hybrid Additive/Subtractive Manufacturing

Abstract

In the past 5 years, oxygen-permeable films have been widely used for continuous additive manufacturing. These films create a polymerization inhibition zone that facilitates continuous printing in the additive mode of fabrication. Typically, oxygen-permeable films made out of Teflon are currently used. These films are expensive and are not commonly available. Hence, this research work investigates the feasibility of using commonly available low-cost oxygen-permeable films made from polydimethylsiloxane (PDMS) and polyurethane for continuous additive manufacturing. We also characterize the ablation depth range that can be achieved using these films and the potential use for subtractive ablation-based manufacturing as well as hybrid additive/ subtractive manufacturing. Results demonstrate that the PDMS films (600 lm thick) can be used for both additive and subtractive modes, whereas spin-coated PDMS thin film (40 lm thick) on glass coverslip and breathe-easy polyurethane film (20 lm thick) laminated on glass coverslip are suitable only for additive mode of fabrication. The latter two films are oxygen impermeable, however, they retain oxygen, which is capable of creating dead zone and thereby facilitates continuous printing. We anticipate that this work will help researchers to choose the appropriate oxygen-permeable film for continuous additive, subtractive, and hybrid additive/ subtractive manufacturing of complex three-dimensional structures for a range of applications.

Droplet bioprinting of acellular and cell-laden structures at high-resolutions

“…Three-dimensional (3D) bioprinting encompasses a set of technologies that have been widely used to generate tissue constructs for several applications [1][2][3][4][5][6][7]. Extrusion-based 3D bioprinting has found wide acceptance in the field with applications ranging from drug screening, disease modeling, tissue repair, and regenerative medicine.…”

“…Inkjet bioprinting is non-contact method to print tissue analogs with high cell viability and scalability, however challenges related to printing thick tissues with bioinks properties within a narrow viscosity range as limited it use in the field [23,24]. Among the many bioprinting methods, digital light projection (DLP) based bioprinting methods are capable of printing both acellular and cell-laden scalable 3D architecture at high resolutions, speeds, and overall fidelity (table S1) [3,4,7,[25][26][27][28][29]. These methods use a liquid crystal display or a digital micromirror device (DMD) to generate digital masks that can spatially pattern and project light onto a vat or reservoir filled with liquid photo-sensitive bioink of resin to print 3D constructs via rapid crosslinking in a layer-by-layer manner [30][31][32].…”

4D Additive–Subtractive Manufacturing of Shape Memory Ceramics

“…[ 1 ] This tradeoff can be eliminated by integrating AM and subtractive manufacturing (SM) processes, and the concept of additive–subtractive manufacturing (ASM) can facilitate the development of rapid, precise, and scalable 3D printing technologies. [ 3 ]…”

Printing Double-Network Tough Hydrogels Using Temperature-Controlled Projection Stereolithography (TOPS)

“…Bottom-up projection stereolithography (PSLA) has emerged as the favorite light-based 3D printing method due to its capability to make customized parts with microscale resolution and superior design flexibility. − A typical setup consists of spatially modulated light patterns projected through a transparent bottom window to cross-link photosensitive liquid resins in XY plane before moving the stage up ( z -direction) to print the structure in a layer-by-layer or layerless continuous manner. ,, Unfortunately, many DN resins do not meet the criteria of low viscosity and rapid photo-cross-linking at specific wavelengths. For instance, thermoreversible sol–gel transitions require elevated temperatures beyond the operating range of current printers, while reaction durations and cross-linking times for orthogonal click chemistries remain too long for PSLA (hours). , New strategies that combine PSLA technology with DN hydrogels could potentially lead novel soft devices with superior mechanical properties.…”