Projection Microstereolithography Research Articles

Controlled Mechanical Property Gradients Within a Digital Light Processing Printed Hydrogel-Composite Osteochondral Scaffold.

Tissue engineered scaffolds are needed to support physiological loads and emulate the micrometer-scale strain gradients within tissues that guide cell mechanobiological responses. We designed and fabricated micro-truss structures to possess spatially varying geometry and controlled stiffness gradients. Using a custom projection microstereolithography (μSLA) system, using digital light projection (DLP), and photopolymerizable poly(ethylene glycol) diacrylate (PEGDA) hydrogel monomers, three designs with feature sizes < 200μm were formed: (1) uniform structure with 1MPa structural modulus ( ) designed to match equilibrium modulus of healthy articular cartilage, (2) = 1MPa gradient structure designed to vary strain with depth, and (3) osteochondral bilayer with distinct cartilage ( = 1MPa) and bone ( = 7MPa) layers. Finite element models (FEM) guided design and predicted the local mechanical environment. Empty trusses and poly(ethylene glycol) norbornene hydrogel-infilled composite trusses were compressed during X-ray microscopy (XRM) imaging to evaluate regional stiffnesses. Our designs achieved target moduli for cartilage and bone while maintaining 68-81% porosity. Combined XRM imaging and compression of empty and hydrogel-infilled micro-truss structures revealed regional stiffnesses that were accurately predicted by FEM. In the infilling hydrogel, FEM demonstrated the stress-shielding effect of reinforcing structures while predicting strain distributions. Composite scaffolds made from stiff μSLA-printed polymers support physiological load levels and enable controlled mechanical property gradients which may improve in vivo outcomes for osteochondral defect tissue regeneration. Advanced 3D imaging and FE analysis provide insights into the local mechanical environment surrounding cells in composite scaffolds.

A 3D-printed microhemispherical shell resonator with electrostatic tuning for a Coriolis vibratory gyroscope

The emergence of microhemispherical resonant gyroscopes, which integrate the advantages of exceptional stability and long lifetime with miniaturization, has afforded new possibilities for the development of whole-angle gyroscopes. However, existing methods used for manufacturing microhemispherical resonant gyroscopes based on MEMS technology face the primary drawback of intricate and costly processing. Here, we report the design, fabrication, and characterization of the first 3D-printable microhemispherical shell resonator for a Coriolis vibrating gyroscope. We remarkably achieve fabrication in just two steps bypassing the dozen or so steps required in traditional micromachining. By utilizing the intricate shaping capability and ultrahigh precision offered by projection microstereolithography, we fabricate 3D high-aspect-ratio resonant structures and controllable capacitive air gaps, both of which are extremely difficult to obtain via MEMS technology. In addition, the resonance frequency of the fabricated resonators can be tuned by electrostatic forces, and the fabricated resonators exhibit a higher quality factor in air than do typical MEMS microhemispherical resonators. This work demonstrates the feasibility of rapidly batch-manufacturing microhemispherical shell resonators, paving the way for the development of microhemispherical resonator gyroscopes for portable inertial navigation. Moreover, this particular design concept could be further applied to increase uptake of resonator tools in the MEMS community.

Projection Micro Stereolithography of Skin Layered Microporous Polymer Membranes As a Separator for Li-Ion Batteries

Commercial liquid electrolyte lithium-ion batteries (LIBs) traditionally incorporate microporous polymer membranes, or separators, to isolate electrode contact and enable ionic transport. Although they do not actively participate in cell chemistry, well-designed separators can influence cell performance and safety, and thus, are essential components of a cell. Current separator manufacturing processes include "wet" or "dry" mechanical stretching , phase inversion, and evaporation-induced phase separation. However, these processes have limited morphological control of geometry and layered structures. Additive manufacturing techniques have been used to rapidly prototype materials that have both high customizability and fine microstructural control. We investigate hexanediol diacrylate (HDDA) as a polymer system using projection micro-stereolithography, a layer-by-layer photopolymerization technique, to develop separators with controlled microstructures for Li-ion batteries. We successfully fabricate a unique polymer architecture of alternating nanometer thin skin layers and microporous network. The fine control of printing parameters (i.e., printing platform, skin layers, and exposure time), results in tunable porosity and morphology. This unique approach to manufacturing LIB separators provides hierarchical homogeneity for more uniform Li-ion transport. It’s potential as a LIB separator is explored by characterizing its electrolyte wettability, thermal tolerance, electrochemical properties, and mechanical stability. Finally, lithium symmetric cells using the HDDA microporous membranes are evaluated against Celgard 2325 separators. This work provides a promising new route for developing separators using additive manufacturing techniques to enable high performance Li-ion batteries.

Enhanced Transport in Electrochemical Reactors Using Advanced 3D Printed Electrodes

Water electrolyzers employ porous architectures to facilitate the transport of mass and charge. Ensuring effective transport can improve energy efficiency and unlock stable operation at higher current densities. In order to realize these improvements, however, research needs to show the relationship between pore structure and performance. Advances in 3D printing research have enabled the manufacture of functional, electrically conductive porous materials at ever finer length scales and larger build areas. Using electrodes manufactured via projection microstereolithography (PuSL), we first show how this structural control can lead to computationally optimized electrodes which minimize the total power losses of a model single phase reaction. The physics of gas bubble transport in water electrolyzers is more complicated, however. At higher operating current densities, entrained gas bubbles in the triple phase boundary can be a source of degradation by occupying active sites and impeding the flow of ions between electrodes. Using structured pores, controlled surface tension boundaries offer an unprecedented degree of control over gas bubble transport. Integrating these ordered structures into water electrolyzers has the potential to improve the stability of devices at high current densities by guiding bubbles away from the reaction zone and into designed outlets.

Projection Micro-Stereolithography to Manufacture a Biocompatible Micro-Optofluidic Device for Cell Concentration Monitoring.

In this work, a 3D printed biocompatible micro-optofluidic (MoF) device for two-phase flow monitoring is presented. Both an air-water bi-phase flow and a two-phase mixture composed of micrometric cells suspended on a liquid solution were successfully controlled and monitored through its use. To manufacture the MoF device, a highly innovative microprecision 3D printing technique was used named Projection Microstereolithography (PμSL) in combination with the use of a novel 3D printable photocurable resin suitable for biological and biomedical applications. The concentration monitoring of biological fluids relies on the absorption phenomenon. More precisely, the nature of the transmission of the light strictly depends on the cell concentration: the higher the cell concentration, the lower the optical acquired signal. To achieve this, the microfluidic T-junction device was designed with two micrometric slots for the optical fibers' insertion, needed to acquire the light signal. In fact, both the micro-optical and the microfluidic components were integrated within the developed device. To assess the suitability of the selected biocompatible transparent resin for optical detection relying on the selected working principle (absorption phenomenon), a comparison between a two-phase flow process detected inside a previously fully characterized micro-optofluidic device made of a nonbiocompatible high-performance resin (HTL resin) and the same made of the biocompatible one (BIO resin) was carried out. In this way, it was possible to highlight the main differences between the two different resin grades, which were further justified with proper chemical analysis of the used resins and their hydrophilic/hydrophobic nature via static water contact angle measurements. A wide experimental campaign was performed for the biocompatible device manufactured through the PμSL technique in different operative conditions, i.e., different concentrations of eukaryotic yeast cells of Saccharomyces cerevisiae (with a diameter of 5 μm) suspended on a PBS (phosphate-buffered saline) solution. The performed analyses revealed that the selected photocurable transparent biocompatible resin for the manufactured device can be used for cell concentration monitoring by using ad hoc 3D printed micro-optofluidic devices. In fact, by means of an optical detection system and using the optimized operating conditions, i.e., the optimal values of the flow rate FR=0.1 mL/min and laser input power P∈{1,3} mW, we were able to discriminate between biological fluids with different concentrations of suspended cells with a robust working ability R2=0.9874 and Radj2=0.9811.

Programmable self-assembly of microstructures on mimicked three dimensional functional surfaces

Capillary force has been extensively investigated to drive the construction of complex microstructures, though most of those previous self-assembled microstructures were on flat surfaces. In this study, we propose a capillary-force-driven self-assembly strategy working for bionic three-dimensional (3D) functional surfaces. Precisely printed micropillar arrays with an extremely large format using projection micro-stereolithography (PμSL) 3D printing technique are assembled into periodic layered structures with the assistance of ethanol evaporation induced capillary force, though the capillary-force-driven self-assembly micropillars are strongly depend on their spatial arrangement and geometric parameters. Also, large-scale programmable capillary-force-driven self-assembly of micropillars can be achieved by tailoring the arrangements of them for various patterns. We further demonstrate the functions of programmable self-assembly micropillars for the selective capture and release of microparticles. Most significantly, we extend the programmable capillary-force-driven self-assembly of micropillars on 3D bionic curved surfaces with various applications, including the mimicked patterns and selective capturing of microparticles.

Programmable Droplet Bouncing on Bionic Functional Surfaces for Continuous Electricity Generation

AbstractThe natural phenomenon of droplets bouncing on various surfaces holds remarkable potential for applications like water transportation, self‐cleaning, antifreezing, etc. However, achieving precisely controlled patterned droplet bouncing on functional surfaces with accurately controlled factors like bouncing velocity and trajectory in three dimensions remains a formidable challenge. In this context, a concept of bionic hydrophobic functional surfaces composed of mushroom‐like microstructures is introduced. These microstructures are crafted using the projection microstereolithography (PµSL) based 3D printing technique, subsequently coated with a hydrophobic spray. By finely adjusting the geometric attributes and inclination angles of these micromushrooms, the ability is gained to meticulously manipulate the bouncing velocity and trajectory of water droplets. The most optimal performance is demonstrated by a droplet exhibiting a maximal jumping distance and height respectively of 2.5 and 7.1 mm with 50° inclined micromushrooms. Notably, these specially designed micromushrooms orchestrate diverse behaviors in droplet bouncing, encompassing patterned bouncing, antigravity jumps, and directional water transportation. Additionally, the functional surface's adaptable self‐cleaning capability facilitates the harnessing of energy from rainfall on large surfaces, offering potential applications in realms, such as self‐cleaning mechanisms, droplet capture, water conveyance, and clean energy generation.

(Invited) Graphene-Based Scaffolds for Electrochemical Energy Storage

The efficient transport of charge species within energy storage devices is critical to realizing both large power and energy densities, especially when operating under extreme conditions (e.g. ultralow temperatures, high charge/discharge rates, etc.). A number of resistances can contribute to sluggish ion/electron transport in a cell such as charge transfer at interfaces, electrolyte resistance, electrode resistance, and diffusive transport within porous electrodes. Several strategies have been pursued to address these transport limitations. Electrolyte engineering is an effective approach as it can influence both electrolyte resistance and charge transfer resistances. Electrode materials discovery and development is another popular strategy as the charge storage mechanism and electrode resistance play a key role in kinetics of the device. Within electrode materials development, engineering of the electrode pore architecture is an extremely effective strategy to decrease the diffusive transport lengths and electrode resistances. This pore engineering can be achieved through synthetic chemistry for small pores (e.g. <10 um) and via additive manufacturing for larger pores (> 10 um). Here we show how electrolyte engineering and electrode materials development can be used to overcome sluggish transport in graphene-based electrodes. Particular focus will be given to the use of synthetic means to tune to the properties of a graphene aerogel scaffold (e.g. surface area, pore size, mechanical properties) and additive manufacturing to define the larger pore structure to facilitate uniform deposition of active materials (e.g. MnO2) and improve energy density and rate capability of the energy storage device. We explore a number of additive manufacturing techniques (e.g. direct ink write, projection microstereolithography, etc.) to print a variety of lattice structures and computer-guided designs to determine the optimal electrode architecture.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Hyper-anti-freezing bionic functional surface to -90°C.

Freezing phenomenon has troubled people for centuries, and efforts have been made to lower the liquid freezing temperature, raise the surface temperature, or mechanical deicing. Inspired by the elytra of beetle, we demonstrate a novel functional surface for directional penetration of liquid to reduce icing. The bionic functional surface is fabricated by projection microstereolithography (PµSL) based three dimensional printing technique with the wettability on its two sides tailored by TiO2 nanoparticle sizing agent. A water droplet penetrates from the hydrophobic side to the superhydrophilic side of such a bionic functional surface within 20 ms, but it is blocked in the opposite direction. Most significantly, the penetration time of a water droplet through such a bionic functional surface is much shorter than the freezing time on it, even though the temperature is as low as -90°C. This work opens a gate for the development of functional devices for liquid collection, condensation, especially for hyperantifogging/freezing.

Programmable Microfluidics Enabled by 3D Printed Bionic Janus Porous Matrics for Microfluidic Logic Chips.

Numerous structures have been functionally optimized for directional liquid transport in nature. Inspired by lush trees' xylem that enable liquid directional transportation from rhizomes to the tip of trees, a new kind of programmable microfluidic porous matrices using projection micro-stereolithography (PµSL) based 3D printing technique is fabricated. Structural matrices with internal superhydrophilicity and external hydrophobicity are assembled for ultra-fast liquid rising enabled by capillary force. Moreover, the unidirectional microfluidic performance of the bionic porous matrices can be theoretically optimized by adjusting its geometric parameters. Most significantly, the successive programmable flow of liquid in a preferred direction inside the bionic porous matrices with tailored wettability is achieved, validating by a precisely printed liquid displayer and a microfluidic logic chip. The programmable and functional microfluidic matrices promise applications of patterned liquid flow, displayer, logic chip, cell screening, gas-liquid separation, and so on.

High-precision 3D printing of microfluidic devices under sanctions restrictions

The article is devoted to the problem of import substitution of microfluidic chips in the conditions of sanctions restrictions. The stages of chip production are described, a comparison of traditional and additive manufacturing methods is given. The features of the projection microstereolithography method and the materials used are considered in detail. A case study on the introduction of 3D-printing chips for a research organization that is engaged in the selection of surfactants to enhance oil recovery from rocks is presented. The economic efficiency of implementation is analyzed.

Bioinspired Adhesive Manufactured by Projection Microstereolithography 3D Printing Technology and Its Application

AbstractMany methods are used to manufacture bioinspired adhesive arrays such as photolithography and nanoimprinting methods, which are very high cost and time‐consuming. In this manuscript, projection microstereolithography 3D printing method is firstly adopted to prepare the bioinspired dry adhesive in several micrometers, which is low cost, time saving, convenient and can realize rapid, large‐scale, high‐precision, and controllable complex structure manufacture. The morphology and adhesive properties of four kinds of adhesive with flat punch, mushroom‐shaped, suction cup‐shaped, and titled micropillar structures are investigated. Scanning electron microscope (SEM) observation shows that the very regular pattern of the adhesive is generated and no collapse phenomenon is observed. The adhesion test results show the mushroom‐shaped adhesive reach the maximum adhesion of 15 KPa, which can be maintained after repeated uses. The contact angle of the adhesive is 143.7°, showing the good self‐cleaning ability. The mushroom‐shaped adhesive exhibits excellent adhesion property, high repeatability, and good self‐cleaning ability, which is further applied in grasping and transferring various surfaces such as solar panels, printed circuit board, flanges, and so on.

Additively Manufactured 3D Micro-bioelectrodes for Enhanced Bioelectrocatalytic Operation

The drive toward miniaturization of enzyme-based bioelectronics established a need for three-dimensional (3D) microstructured electrodes, which are difficult to implement using conventional manufacturing processes. Additive manufacturing coupled with electroless metal plating enables the production of 3D conductive microarchitectures with high surface area for potential applications in such devices. However, interfacial delamination between the metal layer and the polymer structure is a major reliability concern, which leads to device performance degradation and eventually device failure. This work demonstrates a method to produce a highly conductive and robust metal layer on a 3D printed polymer microstructure with strong adhesion by introducing an interfacial adhesion layer. Prior to 3D printing, multifunctional acrylate monomers with alkoxysilane (-Si-(OCH3)3) were synthesized via the thiol-Michael addition reaction between pentaerythritol tetraacrylate (PETA) and 3-mercaptopropyltrimethoxysilane (MPTMS) with a 1:1 stoichiometric ratio. Alkoxysilane functionality remains intact during photopolymerization in a projection micro-stereolithography (PμSLA) system and is utilized for the sol-gel reaction with MPTMS during postfunctionalization of the 3D printed microstructure to build an interfacial adhesion layer. This leads to the implementation of abundant thiol functional groups on the surface of the 3D printed microstructure, which can act as a strong binding site for gold during electroless plating to improve interfacial adhesion. The 3D conductive microelectrode prepared by this technique exhibited excellent conductivity of 2.2 × 107 S/m (53% of bulk gold) with strong adhesion between a gold layer and a polymer structure even after harsh sonication and an adhesion tape test. As a proof-of-concept, we examined the 3D gold diamond lattice microelectrode modified with glucose oxidase as a bioanode for a single enzymatic biofuel cell. The lattice-structured enzymatic electrode with high catalytic surface area was able to generate a current density of 2.5 μA/cm2 at 0.35 V, which is an about 10 times increase in current output compared to a cube-shaped microelectrode.

Bionic microchannels for step lifting transpiration

Those various cross-sectional vessels in trees transfer water to as high as 100 meters, but the traditional fabrication methods limit the manufacturing of those vessels, resulting in the non-availability of those bionic microchannels. Herein, we fabricate those bionic microchannels with various cross-sections by employing projection micro-stereolithography (PµSL) based 3D printing technique. The circumradius of bionic microchannels (pentagonal, square, triangle, and five-pointed star) can be as small as 100 μm with precisely fabricated sharp corners. What’s more, those bionic microchannels demonstrate marvelous microfluidic performance with strong precursor effects enabled by their sharp corners. Most significantly, those special properties of our bionic microchannels enable them outstanding step lifting performance to transport water to tens of millimeters, though the water can only be transported to at most 20 mm for a single bionic microchannel. The mimicked transpiration based on the step lifting of water from bionic microchannels is also achieved. Those precisely fabricated, low-cost, various cross-sectional bionic microchannels promise applications as microfluidic chips, long-distance unpowered water transportation, step lifting, mimicked transpiration, and so on.

Elastically Isotropic Truss-Plate-Hybrid Hierarchical Microlattices with Enhanced Modulus and Strength.

Bioinspired hierarchical design principles have been employed to create advanced architected materials. Here, a new type of truss-plate-hybrid two-level hierarchical architecture is created, referred to as the ISO-COP hierarchical lattice (isotropic truss at the first level and cubic+octet plate at the second level), in which truss-based unit cells are arranged according to the topology of the plate-based unit cell. Finite element analyses reveal that the ISO-COP hierarchical lattice outperforms the best existing octet-truss hierarchical lattices based on fractal geometries in achieving elastic isotropy and enhanced moduli. According to the designed architecture, ISO-COP and several other comparison hierarchical microlattices are fabricated via projection microstereolithography. In situ compression tests demonstrate that the fabricated ISO-COP microlattices exhibit elastic isotropy and enhanced moduli, as predicted from finite element simulations, and superior strength compared with existing fractal octet-truss hierarchical lattices. Theoretical models are further developed to predict the dependence of modulus and failure modes on two design parameters of the hierarchical lattices, with results in good agreement with those from experiments. This study relates mechanical properties of ISO-COP hierarchical lattices to their architectures at each level of hierarchy and exemplifies a route to harnessing hierarchical design principles to create architected materials with desired mechanical properties.

Development and Characterization of PEGDA Microneedles for Localized Drug Delivery of Gemcitabine to Treat Inflammatory Breast Cancer.

Inflammatory breast cancer (IBC) is one of the most belligerent types of breast cancer. While various modalities exist in managing/treating IBC, drug delivery using microneedles (MNs) is considered to be the most innovative method of localized delivery of anti-cancer agents. Localized drug delivery helps to treat IBC could limit their adverse reactions. MNs are nothing but small needle like structures that cause little or no pain at the site of administration for drug delivery via layers of the skin. The polyethylene glycol diacrylate (PEGDA) based MNs were fabricated by using three dimensional (3D) technology called Projection Micro-Stereo Lithography (PµSL). The fabricated microneedle patches (MNPs) were characterized and coated with a coating formulation comprising of gemcitabine and sodium carboxymethyl cellulose by a novel and inventive screen plate method. The drug coated MNPs were characterized by various instrumental methods of analysis and release profile studies were carried out using Franz diffusion cell. Coat-and-poke strategy was employed in administering the drug coated MNPs. Overall, the methods employed in the present study not only help in obtaining MNPs with accurate dimensions but also help in obtaining uniformly drug coated MNPs of gemcitabine for treatment of IBC. Most importantly, 100% drug release was achieved within the first one hour only.

Superior compressive properties of 3D printed plate lattice mechanical metamaterials

Over the past decades, the demand for high-performance materials with lightweight and enhanced mechanical properties has gradually increased. The cellular structure, theoretically excellent mechanical performance, and tunable low density make the lattice structure an ideal structure. In the past, research on complex structures was limited by manufacturing technology. The advent of additive manufacturing has enabled detailed studies of such lattice structures. Simple Cubic (SC) plate lattice is believed to be capable of reaching the theoretical limitation of mechanical performance in nanoscale ; thus, it is of great significance to explore potential application of this cubic plate lattice. In this work, projection micro-stereolithography (PµSL) was used to print cubic plate lattices. The effect of geometrical parameters on mechanical properties was studied. Results demonstrate that increasing the number of cells leads to a superior increase in compressive strength and energy absorption, which shows obvious mechanical metamaterials properties. Moreover, the specific energy absorption of these polymeric lattices can even outperform stainless steel lattices, indicating that they have great potential for applications in high energy absorption, strength, and light-weighting.

Achieving the theoretical limit of strength in shell-based carbon nanolattices

Recent developments in mechanical metamaterials exemplify a new paradigm shift called mechanomaterials, in which mechanical forces and designed geometries are proactively deployed to program material properties at multiple scales. Here, we designed shell-based micro-/nanolattices with I-WP (Schoen's I-graph-wrapped package) and Neovius minimal surface topologies. Following the designed topologies, polymeric microlattices were fabricated via projection microstereolithography or two-photon lithography, and pyrolytic carbon nanolattices were created through two-photon lithography and subsequent pyrolysis. The shell thickness of created lattice metamaterials varies over three orders of magnitude from a few hundred nanometers to a few hundred micrometers, covering a wider range of relative densities than most plate-based micro-/nanolattices. In situ compression tests showed that the measured modulus and strength of our shell-based micro-/nanolattices with I-WP topology are superior to those of the optimized plate-based lattices with cubic and octet plate unit cells and truss-based lattices. More strikingly, when the density is larger than 0.53 g cm-3, the strength of shell-based pyrolytic carbon nanolattices with I-WP topology was found to achieve its theoretical limit. In addition, our shell-based carbon nanolattices exhibited an ultrahigh strength of 3.52 GPa, an ultralarge fracture strain of 23%, and an ultrahigh specific strength of 4.42 GPa g-1 cm3, surpassing all previous micro-/nanolattices at comparable densities. These unprecedented properties can be attributed to the designed topologies inducing relatively uniform strain energy distributions and avoiding stress concentrations as well as the nanoscale feature size. Our study demonstrates a mechanomaterial route to design and synthesize micro-/nanoarchitected materials.

Ultra-fast programmable human-machine interface enabled by 3D printed degradable conductive hydrogel

Hydrogels are attracting enormous interests in various applications including electronic skins, tissue engineering, drug delivery, and wearable devices due to their marvelous stretchability, conductivity and ultra-high sensitivity. In the present study, we propose a new type of conductive cross-linked hydrogel fabricated by projection microstereolithography (PμSL) based three-dimensional (3D) printing technique which can be completely degraded when submerged in alkaline within tens of seconds. The tensile strengths and conductivity of hydrogels are tested to demonstrate their great performance of flexibility and conductivity. Moreover, the influences of temperature, pH value and chemical compositions on the conductivity and degradation performance of our printable hydrogels are also explored. Based on the merits of our printable hydrogel, the developed hydrogel sensors promise feasible applications of degradable, highly stretchable and conductive wearable devices and transient electronics. Most significantly, hydrogel circuits can be functionally tailored by alkaline and photocurable precursor of the printable hydrogel within tens of seconds, enabling the ultra-fast programmable human-machine interface to acquire electromyogram (EMG) signals for controlling the fingers of an extraman accurately. The present work opens a gate for designing ultra-fast programmable flexible electronics, transient electronics, human-machine interface, etc. with printed degradable conductive hydrogel.

High‐Precision 3D Printing of High‐Strength Polymer‐Derived Ceramics: Impact of Precursor's Molecular Structure

Additive manufacturing (3D printing) offers new opportunities to create complex structures for many applications. The development of suitable precursors for high‐resolution 3D printing of ceramics is increasingly essential to meet evolving material requirements. Herein, a new hybrid preceramic formulation based on thiol‐ene click chemistry for precision printing of polymer‐derived ceramic has been developed to enable the fabrication of complex 3D objects using high‐resolution projection microstereolithography (PμSL). Two low‐odor thiol compounds with either three (trithiol) or four thiols (tetrathiol) moieties have been examined, to investigate the influence of thiol structure on the mechanical properties of converted ceramics. Pyrolysis of the printed green bodies leads to the formation of silicon oxycarbide (SiOC) with high fidelity after polymer‐to‐ceramic transformation. The SiOC printed specimen converted from the tetrathiol formulation (4T) demonstrates excellent mechanical strength surpassing that of the trithiol‐based formulation (3T) and previously reported SiOC preceramic polymers. The ceramic honeycomb fabricated using the tetrathiol compound shows remarkable improvement in compressive strength, which is two times higher than that of the trithiol‐derived ceramic. This work proposes a simple and effective way to formulate 3D printable preceramic polymers through molecular design. The achieved 3D printed SiOC can fulfill the requirement for high‐strength ceramic materials with complex shapes.