3D Printing Research Articles

Improving mechanical properties of 3D printed products through honeycomb structure and deep learning optimization

The use of three-dimensional (3D) Printing has rapidly grown due to its various applications in daily life. However, products made with this technology are not widely adopted because their quality is not yet seen as equal to that of products made with traditional materials. To address this issue, a honeycomb structure model was developed to improve the mechanical properties of the items created using 3D printing technology. This model not only saves materials, but also reduces printing time compared to previous models. The honeycomb structure was designed using a theoretical model, and its components were modified to ensure compatibility with the 3D printing extrusion method. Moreover, deep learning was used to optimise the honeycomb structure model’s boundary conditions by generating contour curves through linear interpolation. This process significantly improved the mechanical strength of the honeycomb structure model compared to structures made using 3D printing technology. The theoretical findings were validated through various material tensile tests conducted under different scenarios. As a result, this model can be used in various industries and products that use 3D printing technology, thanks to the critical role that deep learning in improving its mechanical properties.

Fabrication of hierarchically porous trabecular bone replicas via 3D printing with high internal phase emulsions (HIPEs)

Combining emulsion templating with additive manufacturing enables the production of inherently porous scaffolds with multiscale porosity. This approach incorporates interconnected porous materials, providing a structure that supports cell ingrowth. However, 3D printing hierarchical porous structures that combine semi-micropores and micropores remains a challenging task. Previous studies have demonstrated that using a carefully adjusted combination of light absorbers and photoinitiators in the resin can produce open surface porosity, sponge-like internal structures, and a printing resolution of about 150µm. In this study, we explored how varying concentrations of tartrazine (0, 0.02, 0.04, and 0.08 wt%) as a light absorber affect the porous structure of acrylate-based polymerized medium internal phase emulsions fabricated via vat photopolymerization. Given the importance of a porous and interconnected structure for tissue engineering and regenerative medicine, we tested cell behavior on these 3D-printed disk samples using MG-63 cells, examining metabolic activity, adhesion, and morphology. The 0.08 wt% tartrazine-containing 3D-printed sample (008 T) demonstrated the best cell proliferation and adhesion. To show that this high internal phase emulsion (HIPE) resin can be used to create complex structures for biomedical applications, we 3D-printed trabecular bone structures based on microCT imaging. These structures were further evaluated for cell behavior and migration, followed by microCT analysis after 60 days of cell culture. This research demonstrates that HIPEs can be used as a resin to print trabecular bone mimics using additive manufacturing, which could be further developed for lab-on-a-chip models of healthy and diseased bone.

Modification of chain extension and crosslinking structures of recycled polyester textile for 3D printing filament

AbstractThe increase in amount of polyester textile waste is contributing to the severity of environmental pollution because polyester cannot be easily recycled. To reduce the limits of its recyclability, a value‐added recycling approach should be explored. This work introduces an approach for recycling polyester textiles into 3D printable filaments. To increase recyclability of polyester textiles, the polyester materials are modified by ADR4468 additive. After the polyester is 3D printed, the sample with 1.0 wt% of ADR4468 shows the highest tensile and compressive strength properties compared with 1.5 and 2.0 wt%, owing to its fewer voids between the printed lines, a fish scale‐like morphology that spreads out, and a higher degree of crystallization. Moreover, the mechanism of modification suggests that ADR4468 extends and crosslinks the polyester chains by ring‐opening reactions of epoxy groups of ADR4468 and forms sea‐island structures. The sea‐island structures of bonded polyester branched cores with tangled polyester shell interface areas and unbonded polyester chain areas performed suitable rheological behaviors to recycle polyester textiles for 3D printable filaments production. The filaments can be used to replace commercially available filaments, offer a sustainable option for consumers, and impact both the polyester textile‐related recycling and 3D printing industries.Highlights An approach is proposed to recycle polyester textiles for 3D printing filament The approach uses a mechanical method to recycle polyester textiles Recycled polyesters were modified by ADR4468 to form core‐shell structures Core‐shell structures were separated by short polyesters(sea‐island structure) The structures met rheological behaviors for 3D printing filament

CMC/Gel/GO 3D-printed cardiac patches: GO and CMC improve flexibility and promote H9C2 cell proliferation, while EDC/NHS enhances stability.

In this research, carboxymethyl cellulose (CMC)/gelatin (Gel)/graphene oxide (GO)-based scaffolds were produced by using extrusion-based 3D printing for cardiac tissue regeneration. Rheological studies were conducted to evaluate the printability of CMC/Gel/GO inks, which revealed that CMC increased viscosity and enhanced printability. The 3D-printed cardiac patches were crosslinked with N-(3-dimethylaminopropyl)-n'-ethylcarbodiimide hydrochloride (EDC)/ N-hydroxysuccinimide (NHS) (100:20 mM, 50:10 mM, 25:5 mM) and then characterized by mechanical analysis, electrical conductivity testing, contact angle measurements and degradation studies. Subsequently, cell culture studies were conducted to evaluate the viability of H9C2 cardiomyoblast cells by using the Alamar Blue assay and fluorescence imaging. A high concentration of EDC/NHS (100:20 mM) led to the stability of the patches; however, it drastically reduced the flexibility of the scaffolds. Conversely, a concentration of 25:5 mM resulted in flexible but unstable scaffolds in PBS solution. The suitable EDC/NHS concentration was found to be 50:10 mM, as it produced flexible, stable, and stiff cardiac scaffolds with high ultimate tensile strength (UTS). Mechanical characterization revealed that % the strain at break of C15/G7.5/GO1 exhibited a remarkable increase of 61.03% compared to C15/G7.5 samples. The improvement of flexibility was attributed to the hydrogen bonding between CMC, Gel and GO. The electrical conductivity of 3D printed CMC/Gel/GO cardiac patches was 7.0×10-3 S/cm, demonstrating suitability for mimicking the desired electrical conductivity of human myocardium. The incorporation of 1 wt% of GO and addition of CMC concentration from 7.5 wt % to 15 wt % significantly enhanced relative % cell viability. Overall, although this research is at its infancy, CMC/Gel/GO cardiac patches have potential to improve the physiological function of cardiac tissue.

Evaluation of the Accuracy of 3D Printed Patient-Specific Brain Biopsy Guide Using 3D Volume Rendering Technique in Canine Cadavers.

The objective of this study was to evaluate the accuracy of a CT-based, 3D-printed, patient-specific brain biopsy guide (3D-psBBG) through the application of a transfrontal approach in canine cadavers. A total of ten canine cadavers, with weights ranging from 4.36 to 14.4 kg, were subjected to preoperative CT scans to generate 3D skull models. Customized biopsy guides were created based on these models and manufactured using 3D printing technology. Twenty spinal needle insertions were performed, and the accuracy of needle placement was evaluated through both CT and 3D volume-rendering techniques. The mean needle placement error was 2.1 mm, with no significant differences observed between insertions targeting the fronto-olfactory and piriform lobes. The 3D volume-rendering method demonstrated superior accuracy compared to the CT method, with statistically significant differences in placement errors for both targets. The average time required for the design and manufacture of the guides was 249 min. These findings indicate the high accuracy and potential clinical application of CT-based 3D-psBBG for improving diagnostic outcomes in veterinary neurology.

Kinematic analysis applied to a solar tracker driven by a 4-bar mechanism

This paper presents the kinematic analysis of the eccentric crank-slider and crank-rocker mechanisms applied to control the 1-DOF in a solar tracker focused on improving the conversion of solar energy into electrical energy. The mechanisms for its construction and the kinematic equations that allow to know the state that keeps the movement in the working space of the tracker and its comparative analysis between them are presented. Finally, the construction to scale with 3D printing is shown to validate the functionality of each of the 4-bar systems.

Influence of Printing Angulation on the Flexural Strength of 3D Printed Resins: An In Vitro Study

This study compared the flexural strength of various 3D printed resins fabricated at different building angles (0°, 45°, and 90°). Four groups of resins were tested: Varseo Smile Teeth (Bego GmbH & Co., Bremen, Germany), V-print C&B Temp (Voco GmbH, Cuxhaven, Germany), Bego Triniq (Bego GmbH & Co. KG, Bremen, Germany), and Sprintray Crown (SprintRay, Los Angeles, CA, USA). A digital light processing 3D printer (Asiga MAX UV, NSW, Sydney, Australia) was used to fabricate the samples at the specified build angles (0°, 45°, and 90°) in accordance with the ISO 4049:2019 standard. Flexural strength was measured using a universal testing machine (Instron 5567; Instron Ltd., Norwood, MA, USA), and fracture analysis was performed using a scanning electron microscope (Jeol JSM-6060LV, Tokyo, Japan). Statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS, version 26; IBM Corp., Chicago, IL, USA). Means and standard deviations were calculated for each group, and statistical differences were assessed using one-way ANOVA followed by the Bonferroni post hoc test (p < 0.05). All tested resins exhibited high flexural strength values. The maximum flexural strength was observed in the 0° printed samples (137.18 ± 18.92 MPa), while the lowest values were recorded for the 90° printed samples (116.75 ± 24.74 MPa). For V-print C&B Temp, the flexural strength at 90° (116.97 ± 34.87 MPa) was significantly lower compared to the 0° (156.56 ± 25.58 MPa) and 45° (130.46 ± 12.33 MPa) orientations. In contrast, Bego Triniq samples printed at 45° (148.91 ± 21.23 MPa) demonstrated significantly higher flexural strength than those printed at 0° (113.37 ± 31.93 MPa) or 90° (100.96 ± 16.66 MPa). Overall, the results indicate that the printing angle has a significant impact on the flexural strength of the materials, with some resins showing lower strength values at the 90° build angle.

Application of 3D Printing Technology in Microreactor Fabrication

Application of 3D Printing Technology in Microreactor Fabrication

Comprehensive Study of Stereolithography and Digital Light Processing Printing of Zirconia Photosensitive Suspensions

Zirconia ceramics are used in a wide range of applications, including dental restorations, bioimplants, and fuel cells, due to their accessibility, biocompatibility, chemical resistance, and favorable mechanical properties. Following the development of 3D printing technologies, it is possible to rapidly print zirconia-based objects with high precision using stereolithography (SLA) and digital light processing (DLP) techniques. The advantages of these techniques include the ability to print multiple objects simultaneously on the printing platform. To align with the quality standards, it is necessary to focus on optimizing processing factors such as the viscosity of the suspension and particle size, as well as the prevention of particle agglomeration and sedimentation during printing, comprising the choice of a suitable debinding and sintering mode. The presented review provides a detailed overview of the recent trends in preparing routes for zirconium oxide bodies; from preparing the suspension through printing and sintering to characterizing mechanical properties. Additionally, the review offers insight into applications of zirconium-based ceramics.

Next-generation 3D printed multipurpose prevention intravaginal ring for prevention of HIV, HSV-2, and unintended pregnancy

Globally, nearly half of all pregnancies are unintended, ~1.3 million new human immunodeficiency virus (HIV) infections are reported every year, and more than 500 million people are estimated to have a genital herpes simplex virus (HSV-2) infection. Here we report the first 3D printed multipurpose prevention technology (MPT) intravaginal ring (IVR) for prevention of HIV, HSV-2, and unintended pregnancy. The IVRs were fabricated using state-of-the-art Continuous Liquid Interface Production (CLIP™) 3D printing technology using a biocompatible silicone-urethane based resin. Anti-HIV drug (Dapivirine, DPV), anti-herpes drug (Pritelivir, PTV) and a contraceptive drug (Levonorgestrel, LNG) were loaded in a macaque size IVR (25 mm outer diameter, OD; 6.0 mm cross-section, CS) allometrically scaled from the human size (54 mm OD; 7.6 mm CS) IVR analogue. All three active pharmaceutical ingredients (APIs) were loaded in the IVR using a single-step drug loading process driven by absorption. DPV, PTV, and LNG elicited zero-order release kinetics in vitro in simulated vaginal fluid (SVF) at pH 4 and pH 8 relevant to human and macaque vaginal pH respectively. CLIP 3D printed MPT IVRs remained stable after 6 months of storage at 4 °C with no change in physical, dimensional, or mechanical properties and no change in drug concentration and absence of drug degradation byproducts. The MPT IVRs elicited sustained release of all three APIs in macaques for 28 days with median plasma concentrations of 138 pg/mL (DPV), 18,700 pg/mL (PTV), and 335 pg/mL (LNG). Safety studies demonstrated that the MPT IVRs were safe and well tolerated in the macaques with no observed change or abnormalities in vaginal pH and no significant changes in any of the 22 mucosal cytokines and chemokines tested including pro-inflammatory (IL-1β, IL-6, IL-8, IFN-γ, TNF-α, IL-17, IL-18) and anti-inflammatory (IL-10, IL-12) cytokines while the MPT IVR was in place or after its removal. Additionally, MPT IVRs elicited no observed alterations in systemic CD4+ and CD8+ T cells during the entire study. Collectively, the proposed MPT IVR has potential to expand preventative choices for young women and girls against unintended pregnancy against two highly prevalent sexually transmitted infections (STIs).

Preparation of Cf/Si3N4 composites based on vat photopolymerization combined with precursor infiltration and pyrolysis

AbstractThe development of vat photopolymerization (VPP) 3D printing technology has created the conditions for the fabrication of complex structured Si3N4 ceramics. However, Si3N4 ceramics produced through VPP often lack sufficient mechanical properties, which limiting their applications. This study introduces short carbon fibers (Cf) into the VPP‐Si3N4 ceramics, combined with the polymer infiltration and pyrolysis (PIP) process, to prepare Cf/Si3N4 composites. The effect of Cf content on slurry preparation, green part printing, and mechanical properties of the Cf/Si3N4 composites was systematically investigated. The results indicate that Cf significantly enhances the mechanical properties of Cf/Si3N4 composites. At 6 wt.% Cf content, the samples exhibit the highest strength and fracture toughness, reaching 183.2 MPa and 6.2 MPa·m1/2, respectively, representing increases of 29.7% and 92.3% compared to samples without Cf. The improvement in mechanical properties is partly due to the ‘pinning effect’ of Cf, which enhances interlayer bonding strength in the printed green parts, positively impacting the overall mechanical properties of the composites. Additionally, inherent toughening mechanisms of Cf, such as fiber pull‐out, crack deflection, and crack bridging, further enhance the composite's mechanical properties. This study confirms the feasibility of using Cf to enhance the mechanical properties of VPP‐Si3N4 ceramic.

A Programmable Oral Nanomotor Microcapsule for the Treatment of Inflammatory Bowel Disease

AbstractGiven the unique anatomy and location of inflammatory bowel disease (IBD), oral pharmacological treatment is the mainstay for managing IBD because of its convenience and direct accessibility to the gastrointestinal tract. However, efficient delivery systems must be designed to navigate the harsh gastrointestinal environment during application. Here, an innovative oral drug delivery system was proposed using nanomotor (NM)‐loaded soluble microcapsules for treating IBD. MnO2‐Au‐mSiO2 NMs incorporate partially encapsulated MnO2 antennas that convert reactive oxygen species into oxygen, autonomously propelling the NMs. Astaxanthin (AST), known for its anti‐inflammatory properties, is loaded into the mesoporous silica (mSiO2) of NMs (AST@NMs). AST effectively reduces inflammation and shifts macrophages from a proinflammatory (M1) phenotype to an anti‐inflammatory (M2) phenotype. To protect the nanomotors from harsh digestive conditions and achieve intestinal‐responsive release, using photocurable 3D printing, we fabricated enteric‐coated oral microcapsules (MCs). Additionally, to prevent leakage of AST@NMs, a calcium alginate shell was cured in situ on the surface of the microcapsules (AST@NMs@MCs). In vitro and in vivo, AST@NMs@MCs effectively reduced inflammation, repaired the intestinal barrier, and modulated the gut microbiota. These findings underscore the protective effects of the microcapsules on AST@NM, highlighting their potential as a promising strategy for treating colitis.

Magnetic Field Enhanced Frequency‐Selective Terahertz Detection via 3D Printing Micro‐Helical Stepped and MoTe2 Coated Arrays

AbstractRecent advancements in wireless communication have markedly increased data throughput and decreased latency in progressing toward sixth‐generation (6G) networks, wherein the terahertz (THz) waveband offers significant potential. However, conventional THz sensors often suffer from high noise, low responsivity, and low spectrum efficiency, limiting their effectiveness for THz applications. Here, to address these challenges, a magnetic‐enhanced frequency‐selective is developed THz sensor by depositing an Au‐enhanced active layer of MoTe2 on a designed 3D printing high‐depth micro‐helical stepped structure. This sensor, featuring four characteristic frequency points and an effective area of 107.12 mm2, demonstrated noticeable improvements under a 0.145 mT magnetic field at 0.1 THz: optical responsivity improved by 413.23% (from 3.32 to 17.03 MV W−1), noise equivalent power decreased by 80.51% (from 49.16 to 9.58 pW Hz−1/2), and the detectivity reached 3.30 × 1010 cm·Hz1/2·W−1. This work highlights the potential of integrating 3D microstructures with novel topological materials for practical 6G communication.

Surface Quality as a Factor Affecting the Functionality of Products Manufactured with Metal and 3D Printing Technologies.

Surface engineering is one of the most extensive industries. Virtually all areas of the economy benefit from the achievements of surface engineering. Surface quality affects the quality of finished products as well as the quality of manufactured parts. It affects both functional qualities and esthetics. Surface quality affects the image and reputation of a brand. This is particularly true for cars and household appliances. Surface modification of products is also aimed at improving their functional and protective properties. This applies to surfaces for producing hydrophobic surfaces, anti-wear protection of friction pairs, corrosion protection, and others. Metal technologies and 3D printing benefit from surface technologies that improve their functionality and facilitate the operation of products. Surface engineering offers a range of different coating and layering methods from varnishing and painting to sophisticated nanometric coatings. This paper presents an overview of selected surface engineering issues pertaining to metal products, with a particular focus on surface modification of products manufactured by 3D printing technology. It evaluates the impact of the surface quality of products on their functional and performance qualities.

3D-printed brachytherapy in patients with cervical cancer: improving efficacy and safety outcomes

ObjectiveThis study aims to evaluate the efficacy and safety of 3D printing technology in brachytherapy for cervical cancer, comparing its outcomes with conventional free hand implantation brachytherapy.MethodsA total of 50 cervical cancer patients treated at the First Affiliated Hospital of Gannan Medical College from January 2019 to July 2023 were included in this study. Patients were divided into two groups: 25 patients received intensity-modulated radiotherapy (IMRT) combined with 3D-printed brachytherapy, and 25 patients underwent IMRT combined with free hand brachytherapy implantation. Key indicators analyzed included short-term therapeutic effects, survival outcomes, operation times, the number of CT scans, the number of needles inserted, dosimetric parameters, and complications.ResultsThe use of 3D-printed brachytherapy significantly improved the safety of radiation therapy operations, especially for large tumors (≥ 30 mm), by providing more precise dose distribution and reducing the radiation doses received by critical organs such as the bladder and rectum. Compared to the artificial implant group (88% prevalence), the 3D-printed brachytherapy group showed a significantly lower incidence of radiation enteritis (29.2% prevalence, p < 0.001). There were no significant differences in other complications between the two groups. For instance, the incidence of radiation cystitis was relatively high in the 3D-printed brachytherapy group (79.2% prevalence) compared to the artificial implant group (64% prevalence, p = 0.240). The median follow-up period in this study was 22.5 months [IQR 18–29]. Among the 49 patients included, 43 had cervical squamous carcinoma and 6 had cervical adenocarcinoma. Short-term therapeutic response rates were comparable, with no significant difference in overall survival observed between the two groups.Conclusion3D-printed brachytherapy offers a more effective and safer therapeutic option for patients with cervical cancer, particularly for those with large tumors or complex anatomical structures.

Advanced cryopreservation as an emergent and convergent technological platform

Advanced cryopreservation technologies have the potential to transform organ transplants, biomedical research, food storage, aquaculture, biodiversity repositories, ecological restoration, and numerous other applications. These surpass the capability of existing cryopreservation technologies to extend the life and viability of biological materials at various scales from cells to tissues, organs, and entire organisms. In this article, we demonstrate why innovations in advanced cryopreservation, which we analyze as emergent, convergent platform technologies, raise novel concerns for research ethics and coordination, governance, and equitable access to benefits. As emerging technologies, they may disrupt markets or destabilize social institutions, including the systems that govern the distribution of organs for transplant. As convergent technologies, their impact will be heightened through interaction with other technologies. The technologies that may intensify the social and ethical effects of advanced cryopreservation include information technologies that permit the administration of complex logistics of storage and transport, biotechnologies for the management of floral and faunal species and populations, and 3D printing technologies that may enable the development and distribution of customizable peripheral components of this platform technology. The speed of development among diverse applications of the core platform is likely to vary between sectors in ways that are responsive to public support as well as to ethical constraints, and advancements in any sector will affect the achievement of reliability for the core technology across sectors. We recommend that societal benefits and risks be assessed both in the specific contexts for which peripheral components are developed and for the core technology.

FRESH 3D printing of zoledronic acid-loaded chitosan/alginate/hydroxyapatite composite thermosensitive hydrogel for promoting bone regeneration

The aim of this study was to develop a composite thermosensitive hydrogel for bone regeneration applications. This hydrogel consisted of chitosan, alginate and hydroxyapatite, and was loaded with zoledronic acid as a model drug. The feasibility of three-dimensional (3D) printing of the thermosensitive hydrogel using the extrusion technique was investigated. The 3D printing technique called Freeform Reversible Embedded Suspended Hydrogel (FRESH) printing was employed for this purpose. To characterize the composite hydrogels, several tests were conducted. The gelation time, rheological properties, and in vitro drug release were analyzed. Additionally, the cell viability test on human osteosarcoma MG-63 cells for the composite hydrogel was assessed using an MTT assay. The results of the study showed that the zoledronic acid-loaded composite thermosensitive hydrogel was successfully printed using the FRESH 3D printing technique which was not possible otherwise i.e., by using traditional 3D printing techniques. Further examination of the printed constructs using a Scanning Electron Microscope revealed the presence of porous and layered structures. The gelation times of the composite thermosensitive hydrogel was determined to be 10 and 20 min, respectively for scaffolds with and without HA, indicating the successful formation of the gel within a reasonable time to the FRESH technique. The flow behavior of the hydrogel was found to be pseudoplastic, following a non-Newtonian flow pattern with Farrow’s constant (N) values of 1.708 and 1.853 for scaffolds with and without hydroxyapatite, respectively. In terms of drug release, scaffolds prepared with and without hydroxyapatite reached nearly 100% of zoledronic acid release in 360 h and 48 h, respectively. The cell viability test on human osteosarcoma MG-63 cells using MTT assay has shown increased cell viability % in the case of the composite hydrogel, indicating a biocompatible scaffold. Overall, this study successfully developed a composite thermosensitive hydrogel loaded with zoledronic acid for bone regeneration applications and 3D printed using the FRESH 3D printing technique. The results of this study provide valuable insights into the potential use of this composite hydrogel for future biomedical applications.

Applicability of 3D concrete printing technology in building construction with different architectural design decisions in housing

3D Printing (3DP) technology, one of the layered production methodologies where design and construction configurations can be made with increasing digitalization and Industry 4.0, is one of the leading techniques of the period. 3D Concrete Printing (3DCP) also comes to the fore in the construction industry. The study aims to observe the impact of architectural design decisions on the 3DCP process by developing controlled and consistent design alternatives. Architectural designs developed with different geometric forms in the housing function were subjected to digital planning, 3DCP preparation, and 3DCP prototype final product stages. In the integration of design and 3D concrete printing (3DCP), two key aspects were investigated: (i) the impact of different geometric forms (square, rectangle, hexagon, octagon, circle, and ellipse) on the buildability performance of 3D-printed structures, and (ii) how variations in design details influence printing time, material consumption, cost, and the feasibility of mass production in architectural applications. For the 3DCP process, 3D-printable cementitious mixture was developed, and a 3D printer with dimensions of 100 x 100 x 40 centimeters was used. The results obtained during the printing process were analyzed in comparison with the building evaluation parameters. As a result, the house with circular geometry showed the optimum behavior according to the parameters of buildability, cost, and mass producibility. The circle geometric form provides a 4.2% advantage over the octagon in terms of buildability, a 16.6% advantage over the ellipse in terms of cost, and a 20% advantage over the ellipse in terms of mass producibility.

Orthogonal photochemistry toward spatial reprogramming of 3D-printed liquid crystal elastomers

The versatile actuation of liquid crystal elastomers (LCEs), crucial for future soft robots, is determined by both geometrical shape and mesogen alignment. 3D printing can effectively manufacture complex shapes of LCEs, yet the precise reprogramming of mesogen alignment remains beyond control. To address this challenge, we report an orthogonal photochemistry design to decouple 3D printing and mesogen alignment. The former is achieved through visible light-triggered radical polymerization, whereas the latter can be accomplished via UV irradiation. While seeking suitable UV-sensitive chemistries compatible with traditional photocurable 3D printing, we demonstrate that the hexaarylbiimidazole structure is capable of dynamic bond exchange upon UV exposure. This remarkable UV responsive dynamic feature enables the programming, erasing, and multiple reprogramming of mesogen alignments for a 3D printed LCE in a spatio-temporal manner. The underlying strategy enables the realization of LCEs with arbitrary reprogrammable actuation, enriching the design strategies for future soft robots.

3D Printed Personalized Colon-targeted Tablets: A Novel Approach in Ulcerative Colitis Management.

Ulcerative colitis (UC) and Crohn's disease (CD) are two types of idiopathic inflammatory bowel disease (IBD) that are increasing in frequency and incidence worldwide, particularly in highly industrialized countries. Conventional tablets struggle to effectively deliver anti-inflammatory drugs since the inflammation is localized in different areas of the colon in each patient. The goal of 3D printing technology in pharmaceutics is to create personalized drug delivery systems (DDS) that are tailored to each individual's specific needs. This review provides an overview of existing 3D printing processes, with a focus on extrusion-based technologies, which have received the most attention. Personalized pharmaceutical products offer numerous benefits to patients worldwide, and 3D printing technology is becoming more affordable every day. Custom manufacturing of 3D printed tablets provides innovative ideas for developing a tailored colon DDS. In the future, 3D printing could be used to manufacture personalized tablets for UC patients based on the location of inflammation in the colon, resulting in improved therapeutic outcomes and a better quality of life.