Gel Materials Research Articles

A phase field solution for modelling hyperelastic material and hydrogel fracture in ABAQUS

The phase field fracture model is attracting significant interest. To model fracture in hyperelastic material and hydrogel, we have implemented a robust two- and three-dimensional phase field method in the commercial finite element code ABAQUS/Standard. The method is based on the rate-independent variational principle of diffuse fracture and also exploits the analogy between the phase field evolution law and the heat transfer equation, enabling the use of Abaqus’ in-built features and sparing the need for defining user elements. The framework is shown to accommodate both staggered and monolithic solution schemes. The approach can properly simulate the fracture for both hyperelastic material and hydrogel under different boundary conditions. Several examples are provided to demonstrate the robustness of the method. The provided source codes and the tutorials make it easy for practicing engineers and scientists to model crack propagation in hyperelastic and gel materials.

Deformable Nanovesicle-Loaded Gel for Buccal Insulin Delivery.

Deformable nanovesicles (DNVs) have been widely used in oral mucosal delivery studies of biomolecular drugs. However, their development for oral mucosal preparations has been limited by their physical and chemical instability, the need for small oral volumes, and the complexity of the oral microenvironment. This study aimed to develop a more suitable buccal delivery system for DNVs with improved storage stability. Preliminary stability studies investigated different gel types, the effects of different hydrophilic gel matrices, and matrix temperature sensitivity using DNVs loaded with insulin-phospholipid complex (IPC-DNVs). A temperature-sensitive gel encapsulating IPC-DNVs (IPC-DNV-TSG) prepared with 2% w/v gelatin was stable at 4 °C for three months and maintained an excellent hypoglycemic effect. The delivery efficiency of IPC-DNVs and IPC-DNV-TSG was compared using a TR146 cell model, revealing that cell viability remained high. Cellular uptake was slightly lower for IPC-DNV-TSG than for IPC-DNVs, but total transport did not differ significantly between the two groups, which may have been related to the viscosity of IPC-DNV-TSG and the hydrophilicity, cell adhesion properties, and biocompatibility of gelatin. Moreover, neither IPC-DNVs nor IPC-DNV-TSG induced significant mucosal irritation in rabbit tongue tissue sections. The study findings demonstrate a promising method for possible use as oral mucosal delivery of peptide drugs.

Integrating pressure sensor control into semi-solid extrusion 3D printing to optimize medicine manufacturing

Semi-solid extrusion (SSE) is a three-dimensional printing (3DP) process that involves the extrusion of a gel or paste-like material via a syringe-based printhead to create the desired object. In pharmaceuticals, SSE 3DP has already been used to manufacture formulations for human clinical studies. To further support its clinical adoption, the use of a pressure sensor may provide information on the printability of the feedstock material in situ and under the exact printing conditions for quality control purposes. This study aimed to integrate a pressure sensor in an SSE pharmaceutical 3D printer for both material characterization and as a process analytical technology (PAT) to monitor the printing process. In this study, three materials of different consistency were tested (soft vaseline, gel-like mass and paste-like mass) under 12 different conditions, by changing flow rate, temperature, or nozzle diameter. The use of a pressure sensor allowed, for the first time, the characterization of rheological properties of the inks, which exhibited temperature-dependent, plastic and viscoelastic behaviours. Controlling critical material attributes and 3D printing process parameters may allow a quality by design (QbD) approach to facilitate a high-fidelity 3D printing process critical for the future of personalized medicine.

Improving textural properties of gluten‐free veggie sausage with egg white proteins

AbstractGluten and gums are usually used in veggie sausage for textural purposes; however, they are not label‐friendly for consumers with gluten sensitivity or consumers looking for clean‐label foods. Therefore, two commercial egg white proteins (P110 and M200) were studied at different levels (0%–10%) to substitute gluten or xanthan gum. The veggie sausages were subjected to color, texture, length, and weight loss evaluations. M200 significantly improved the texture of sausages and exhibited the most similar texture profile as a commercial meat sausage. The overall texture‐enhanced capability of gel materials was ranked in the order of 5% M200 > 5% P110 ≥ 3% Gluten ≥ 1.3% Xanthan Gum. Egg white proteins did not significantly affect the color, length, and weight loss of sausages. Raman spectra revealed that M200 gel had a higher α‐helix structure than P110 gel, which indicated that M200 formed an ordered gel by reforming tyrosine at Raman shift 833 and 860 cm−1 inside while P110 formed a disordered gel by exposing tyrosine. This study demonstrated that M200 would substitute both the gluten and xanthan gum for improving the texture of veggie sausages. The findings may also be applied to other meat analogs targeting gluten‐free and label‐friendly purposes.

Numerical and experimental investigation of desiccant cooling system using metal organic framework materials

• Modelling of stationary desiccant wheel coated with different metal organic framework adsorbent materials (MIL-100(Fe), MIL101(Cr), CPO-27(Ni), Aluminium fumarate). • Develop new equilibrium equations from the isotherms related to these MOFs. • New experimental data and numerical data for stationary honeycomb desiccant wheel coated with Aluminium Fumarate was generated. • MOF materials coating process and performance comparisons with different humidifier air speeds. Evaporative cooling consumes fraction of the electricity required by the vapour compression refrigeration system but is only effective in dry weather conditions. A promising method for controlling the incoming air humidity is to use a desiccant wheel before the evaporative cooler. Currently, most desiccant cooling systems employ conventional materials like silica gel or zeolites which have low water uptake. Metal Organic Framework (MOF) materials are new class of meso -porous material with high water adsorption capabilities (∼1.5 kg/kgads). Using numerical modelling and experimental testing, this paper investigates the use of four MOF materials namely CPO27(NI), MIL100(Fe), MIL-101(Cr), Aluminium Fumarate and silica gel on the performance of a stationary desiccant heat exchanger (honeycomb Aluminium structure coated with MOF desiccant material) in terms of the Coefficient of performance (COP) and moisture removal rate. Numerical results showed that Aluminium fumarate produced the highest COP of 0.65 with water removal rate of 12.65 g/kg dry air and MIL-101(Cr) produced the highest moisture removal of 15.99 g/kg dry air but with COP of 0.44 compared to silica gel and other MOF materials used. Experimental tests were carried out using honeycomb structure coated with Aluminium fumarate as the stationary desiccant wheel and results were compared to numerical modelling showing good agreement with maximum deviation of 13%. Experimental and modelling results showed that the rate of moisture removal increases with the increase of air inlet humidity and with the decrease of incoming air speed. Also, results showed that the highest moisture removal occur after the first 2 min from starting the dehumidification process highlighting the advantage of using MOF materials.

Enhancement of the Catalytic Performance and Operational Stability of Sol-Gel-Entrapped Cellulase by Tailoring the Matrix Structure and Properties.

Commercial cellulase Cellic CTec2 was immobilized by the entrapment technique in sol–gel matrices, and sol–gel entrapment with deposition onto magnetic nanoparticles, using binary or ternary systems of silane precursors with alkyl- or aryl-trimethoxysilanes, at different molar ratios. Appropriate tailoring of the sol–gel matrix allowed for the enhancement of the catalytic efficiency of the cellulase biocatalyst, which was then evaluated in the hydrolysis reaction of Avicel microcrystalline cellulose. A correlation between the catalytic activity with the properties of the sol–gel matrix of the nanobiocatalysts was observed using several characterization methods: scanning electron microscopy (SEM), fluorescence microscopy (FM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA/DTA). The homogeneous distribution of the enzymes in the sol–gel matrix and the mass loss profile as a function of temperature were highlighted. The influence of temperature and pH of the reaction medium on the catalytic performance of the nanobiocatalysts as well as the operational stability under optimized reaction conditions were also investigated; the immobilized biocatalysts proved their superiority in comparison to the native cellulase. The magnetic cellulase biocatalyst with the highest efficiency was reused in seven successive batch hydrolysis cycles of microcrystalline cellulose with remanent activity values that were over 40%, thus we obtained promising results for scaling-up the process.

Controlled Delivery and Photopatterning of Mechanical Properties in Polysaccharide Hydrogels Using Vanadium Coordination and Photochemistry.

Incorporation of the transition metal ion V(V) into hydrogels has been used to impart photoresponsive behavior, which was used to tune materials properties during light irradiation. The photoreaction in QHE-cellulose/agarose hydrogels coordinated with vanadium was evidenced by a clear color change of yellow to blue through a green intermediate. This color change was attributed to the reduction of V(V) to V(IV) as described in our previous work. A concomitant oxidative breakdown of the polysaccharide chain was noticeable upon the reduction of V(V) with a decrease in stiffness (G') of the hydrogel material. This reduction of the metal ion and breakdown of polysaccharide chain induced irreversible changes in the microstructure of the hydrogel, enabling the controlled delivery of V(IV) and/or encapsulated cargo. Scanning electron microscopy studies showed an increase in pore sizes and guest cavity formation during irradiation. In addition to the significant drop in mechanical properties like storage and loss modulus in the gel materials, a viscosity drop in the polymer solution was observed through irradiation, indicating breakdown of the polysaccharide chain. A photomask can be used to create discrete patterns on these materials upon irradiation.

Surfactant-template sol-gel protective coatings for cast iron corrosion: Effect of the surfactant type and concentration

Different surfactants-template tetraethylorthosilicate-3-mercaptopropyl-trimethoxysilane (TEOS-MPTMS) sol–gel materials are prepared by the hydrolysis of silane precursors, in presence of the surfactant. Three surfactants are used, cationic cetyltrimethylammonium bromide (CTAB), non-ionic TritonTM X-100, and anionic sodium dodecyl sulfate (SDS). Prepared sol–gel materials are applied as protective coatings for cast iron corrosion in 0.5 mol.L-1 HCl. The protection efficiency is estimated by electrochemical measurements. Structural and surface properties of the prepared sol–gel materials are examined by FTIR and scanning electron microscope (SEM) and are affected by the surfactant species and concentration. Surfactant-template sol–gel materials acquire higher porosity than the free material. However, the presence of the surfactant stabilizes the silane network formation, and facilitates the protection performance, especially at lower and intermediates surfactant amounts. The presence of TritonTM X-100 and CTAB enhance the protection performance of the sol–gel coatings, average efficiencies are 95 and 86 %, respectively. On the other hand, SDS-template sol–gel coatings offer lower efficiency and can not be used as protective coatings at high SDS concentrations due to the repulsion between SDS and negatively charged silanolate groups, which results in a highly unstabilized sol–gel structure with a distorted morphology. The proposed surfactant-template sol–gel coatings show excellent operational stability in the corrosive medium for a long time.

Study of Concrete Surface Coatings Using Thermosensitive Fluorescent Microcapsules Capable of Indicating Damage.

A new type of concrete surface gel coating using thermosensitive fluorescent (TSF) microcapsules was proposed to monitor micro-cracks of cement-based materials. The gel materials can adhere other materials, and the incorporation of microcapsules into the gel coating can be cured on various structural surfaces. Zinc sulfide and phenyl acetate were encapsulated into a polymethyl methacrylate shell to prepare the TSF microcapsules by a solvent evaporation method. When micro-cracks are generated on the surface of the gel coating, the ruptured TSF microcapsules burst out, fill the damaged area, and then emit fluorescence after being excited at ambient temperature. It was found that the brightness of the fluorescence increased with increasing temperature from 80–110 °C. When the concentration of TSF microcapsules was 15% of the mass of the gel coating, the cement-based damage-sensing material had sufficient damage-indicating effects, and the fluorescence brightness of the crack location remained even after a long time. It is expected that this study will provide an effective and intuitive method for crack location detection of cement-based materials.

Synthesis and properties of environmentally friendly double‐network fire fighting gel: Based on natural polymer/industrial solid waste

AbstractIn this paper, a new kind of environmental friendly double‐network gel material was prepared. The first network structure was formed by the graft copolymerization of sodium lignosulfonate (LS) and acrylic acid (AA), and the second network structure was formed by the chelation reaction of sodium alginate (SA) and carbide slag clarified solution (Ca2+). Through an orthogonal experiment, the effects of raw material addition on the compressive strength and apparent viscosity of the gel were analyzed. According to the analysis results, the optimal experimental ratio was obtained, i.e., 2 wt% of LS, 0.25 wt% of SA, 15 wt% of AA, 0.1 wt% of MBA and 0.3 wt% of APS. Furthermore, the structure of the gel are characterized by FTIR, XRD, SEM, XPS, and TG‐DTG, and the results prove that the gel successfully polymerized and a stable three‐dimensional network structure is formed. The results of water absorption experiment disclose that the gel is sensitive to ions and pH, and the water absorption rate reaches 121.25 times. In addition, the results of the air leakage experiment and fire extinguishing experiment show that the gel can effectively cover the surface of crushed coal and densely fill the gaps, demonstrating a good plugging capability and fire extinguishing capability.

Synthesis of a highly active Nb2O5 for 1,2-cyclohexanediol production

A commercial niobium oxide was used to form a gelled material, which was lyophilized producing a novel polyoxoniobate catalyst (L-AmNbO) containing peroxo groups. The activity of this new catalyst was assessed through oxidation reactions of the cyclohexene. In the presence of L-AmNbO catalyst, the oxidation of cyclohexene with H2O2 reached 90% of conversion after 12 h at 75 °C, with selectivity for 1,2-cyclohexanediol (∼ 50%). The catalytic results and the surface properties of this new material indicated that it can be a promising catalyst for niobium compounds applications in the selective oxidation of cyclohexene.

Gigantic Effect due to Phase Transition on Thermoelectric Properties of Ionic Sol–Gel Materials

AbstractSol–gel phase transition in ionic thermoelectrical (i‐TE) materials induces large rapid change in viscosity and ionic transport process and is thus expected to yield a drastic variation in thermoelectric properties, crucial in low‐grade waste heat harvesting and wearable electronic applications. In this study, four types of i‐TE materials are prepared and examined. For the first time, a large rise in the thermopower by 6.5 times during the sol–gel transition of poloxamer/LiCl system is observed, an even greater ionic figure of merit by ≈23 times. The phenomenon is found to be universal as the large variation in thermopower is confirmed in the other transitional materials. The study further reveals the mechanism and proposes a model that deals with the whole process. Finally, six factors influencing the huge variation of the thermopower during the phase‐transition are probed and light is shed on the possible gigantic changes of thermopower during the phase transition. A possible route is uncovered to design and control the desired thermoelectric performances of materials, which can lead to a new sight in tunable i‐TE devices for low‐heat energy harvesting applications.

Improved transdermal delivery of valsartan using combinatorial approach of polymeric transdermal hydrogels and solid microneedles: an ex vivo proof of concept investigation

Valsartan (VAL) is used as a first-line agent to treat hypertension. However, VAL exhibits poor absorption and low bioavailability when administrated orally. To overcome these issues, VAL transdermal gel was developed in this study, where Carbopol was used as the gel matrices. Additionally, solid microneedles (Dermaroller®) with various needle lengths were combined with transdermal gel to improve its permeation across the stratum corneum as a skin barrier. Developed formulations were further evaluated for various parameters, including pH, viscosity, spreadability, extrudability, gel strength, drug content, ex vivo permeation, in vitro release, occlusivity, and hemolysis. The results showed that all formulations exhibited desired physical characteristics without any potential to cause toxicity. Moreover, this approach showed that using microneedles could significantly enhance the permeation of VAL up to 3 folds compared to untreated skin. The use of microneedles 1.5 mm was found to be the optimum combination to improve VA permeation without affecting skin integrity. As much as 1.69 ± 0.004 mg of VAL permeated after 8 h. Finally, it could be concluded that this work had successfully developed a new approach for VALS drug delivery and could potentially show a significant impact on the treatment of hypertension. Further in vivo work should be considered.

Halloysite nanotubes-based composite material with acid/alkali dual pH response and foliar adhesion for smart delivery of hydrophobic pesticide

Smart pesticide delivery systems with pH response are arousing huge interests recently, but single pH sensitivity may bring about constraint in different agricultural situations. We have developed a novel type of responsive material with acid/alkali dual pH sensitivity to deliver hydrophobic pesticide by the combination of acid-sensitive calcium ion (Ca2+)-ethylenediamine tetraacetate (EDTA2-) complex and base-sensitive calcium alginate. During the loading of chlorpyrifos, assembly occurs spontaneously by mixing Ca2+-modified acid-treated halloysite nanotubes (a-HNTs) with EDTA2-, followed by the functionalization of alginate gel to obtain the foliar-adhesive pesticide, namely HCECA (each letter representing halloysite, Ca2+, EDTA2-, chlorpyrifos and alginate, respectively). With loading capacity and loading efficiency of chlorpyrifos at 130 mg/g and 65 %, this engineered pesticide exhibits characteristic sustained release behavior of chlorpyrifos with dual pH response, displaying the release ratio of 58 % and 83 % in 24 h at pH = 4.0 and pH = 8.5, respectively, which is further demonstrated by prolonged control efficiency of corn borers. Owing to the strong interaction of alginate with plant leaves, the foliar adhesion property of HCECA against rain rinsing was strengthened by 86 % and 45 %, in comparison to pristine chlorpyrifos and HCEC (the control pesticide without alginate). The stability of HCECA was investigated, showing its resistance to high temperature (50 °C) and ultraviolet irradiation. Notably, the carrier material shows excellent biocompatibility by testing toxicity on zebrafish. Featured by green preparation, acid/alkali dual pH response and multifaceted stability, the halloysite nanotubes-based gel material serves as a promising carrier for hydrophobic pesticide to be applied in controlled management of agricultural hazards.

Exploring the In Situ Formation Mechanism of Polymeric Aluminum Chloride-Silica Gel Composites under Mechanical Grinding Conditions: As a High-Performance Nanocatalyst for the Synthesis of Xanthene and Pyrimidinone Compounds.

The use of mechanical ball milling to facilitate the synthesis of organic compounds has attracted intense interest from organic chemists. Herein, we report a new process for the preparation of xanthene and pyrimidinone compounds by a one-pot method using polymeric aluminum chloride (PAC), silica gel, and reaction raw materials under mechanical grinding conditions. During the grinding process, polymeric aluminum chloride and silica gel were reconstituted in situ to obtain a new composite catalyst (PAC–silica gel). This catalyst has good stability (six cycles) and wide applicability (22 substrates). The Al–O–Si active center formed by in situ grinding recombination was revealed to be the key to the effective catalytic performance of the PAC–silica gel composites by the comprehensive analysis of the catalytic materials before and after use. In addition, the mechanism of action of the catalyst was verified using density functional theory, and the synthetic pathway of the xanthene compound was reasonably speculated with the experimental data. Mechanical ball milling serves two purposes in this process: not only to induce the self-assembly of silica and PAC into new composites but also to act as a driving force for the catalytic reaction to take place. From a practical point of view, this “one-pot” catalytic method eliminates the need for a complex preparation process for catalytic materials. This is a successful example of the application of mechanochemistry in materials and organic synthesis, offering unlimited possibilities for the application of inorganic polymer materials in green synthesis and catalysis promoted by mechanochemistry.

The micromorphology and large amplitude oscillatory shear behaviors of hydrocarbon gel fuels filled with fumed silica and aluminium sub-microparticles

The gel network structure filled with attractive nanoparticles (NPs) significantly affects the viscoelasticity of the nanocomposites, which is poorly understood and troubles industrial processes. In this work, the nanoparticle gel matrices were prepared with hydrophilic fumed silica (FS), and filled with aluminium sub-microparticles (Al SMPs) loading in the range of 10%− 50%. The effects of particle content and composition on the large amplitude oscillatory shear (LAOS) behaviors are investigated by stress decomposition methods. Meanwhile, the higher harmonics and the Chebyshev harmonics coefficients were obtained. We found that the gels exhibit consistent progressive stiffening with particles filling, companying with plastic transformation and weak strain overshoot (WSO). With aluminum increasing, nonlinear viscoelastic responses gradually weaken in LAOS, severely decreasing the linear viscoelastic (LVE) region, and were validated by strain stiffening index S, T and high-order harmonics. In confocal microscopy (CFM) images, the aluminum particles were fluorescently labeled and found to be adhered together with FS clusters. This article could provide a perspective on understanding the flow mechanism of particulate network structure by combining morphological details and LAOS behaviors.

Preparation of In Situ ZIF-9 Grown on Sodium Alginate/Polyvinyl Alcohol Hydrogels for Enhancing Cu (II) Adsorption from Aqueous Solutions

Metal–organic framework materials(ZIF-9) were loaded on Sodium alginate/polyvinyl(PVA/SA) hydrogel by in situ growth method for adsorption of heavy metal Cu (II). The structure of hydrogels composited with MOFs and polymers was designed to improve the poor mechanical properties of natural polymer gel materials and the inconvenience of powdered MOFs materials in practical applications. The adsorption results showed that the optimum adsorption process of Cu (II) pH was 5.0. The adsorption kinetics and isotherm suggest that the adsorption process follows the Freundlich isotherm and the pseudo-second-order models. The experimental maximum adsorption capacity was 98.98 mg/g, 2.6 times and 1.5 times higher than ordinary SA and PVA/SA hydrogel spheres. Synthesized hydrogel spheres were characterized by FT-IR, SEM, XRD, and XPS, which confirmed that MOF materials have grown in situ on PVA/SA hydrogel spheres. More importantly, PVA/SA@ZIF-9 exhibited exceptional mechanical stability and showed excellent recycling capability in the cyclic adsorption process.

Synergistic and counteractive effects of Bi-component plasticizers on structure and electric field-induced bending actuation behaviors of poly (vinyl chloride) (PVC) gels

Electroactive dielectric polymer gels (DPGs) have important applications in soft robots, wearable electronics, and biomedical devices etc. However, the relationship between structure and electromechanical properties of DPGs have not been fully understood so far. In this work, the effect of the bi-component plasticizers on the structure, mechanical properties, dielectric properties, and electric field induced dynamic bending actuation behaviors of plasticized poly (vinyl chloride) (PVC) gels with free electrodes were investigated using the dibutyl adipate (DBA) as major plasticizer and the branch structured bio-based triethyl 2-acetylcitrate (ATEC) or triethyl citrate (TEC) as minor second plasticizer (30 wt% of bi-component plasticizer). The PVC gel films bend towards the anode side when applied electric field under free electrodes measurement condition. The electric field induced capacitance change of PVC gels was important factor to influence the bending displacement, which were influenced by the interactions between plasticizers and PVC chains in PVC gels. The bending displacement of PVC/DBA/TEC and PVC/DBA/ATEC gels is about 80% and 140% of PVC/DBA at 7.2 kV (corresponding to 180 V/mm of nominal electric field), respectively. The synergistic and counteractive effects of bi-component plasticizers on the bending actuation of PVC gels are mainly attributed to the competition between plasticization effect of PVC and interactions of inter-plasticizers. Our results provide a new insight for the design of high performance electroactive dielectric polymer gel materials.

Birefringence effect studies of collagen formed by nonenzymatic glycation using dual-retarder Mueller polarimetry.

.Significance: Nonenzymatic glycation of collagen covalently attaches an addition of sugar molecules that initially were involved in a reversibly reaction with amino groups on the protein. Due to the ultimate formation of stable irreversible advanced glycation end products, the process of glycation leads to abnormal irreversible cross-linking, which ultimately accumulates with age and/or diabetes in the extracellular matrix, altering its organization.Aim: We report the use of dual-retarder Mueller polarimetry in conjunction with phase retardance to differentiate collagen cross-linking in a normal collagen gel matrix from that in tissues with nonenzymatic cross-linking.Approach: A dual-liquid crystal-based Mueller polarimetry system that involves electronic modulation of polarization state generators (PSGs) was employed to produce all types of polarization states without moving any part and enable detection of the signal directly using a Stokes polarimeter. The linear phase retardance response was obtained for the characterization of the solution and gel forms of collagen using differential Mueller matrix analysis.Results: We found that linear phase retardance measurements via differential Mueller matrix polarimetry successfully differentiated collagen gel matrices with different degrees of cross-linking formed by a nonenzymatic glycation process and demonstrated that this technology constitutes a quick and simple modality.Conclusions: This approach has high sensitivity for studying differences in fibrillar cross-linking in glycated collagen. Further, our work suggests that this method of structural analysis has potential clinical diagnostic value owing to its noninvasive and cost-efficient nature.

Design and Analysis of a 5-Degree of Freedom (DOF) Hybrid Three-Nozzle 3D Printer for Wood Fiber Gel Material

Wood is an organic renewable natural resource. Cellulose, hemicellulose and lignin in wood are used in tissue engineering, biomedicine and other fields because of their good properties. This paper reported that the possibility of wood fiber gel material molding and the preparing of gel material were researched based on the wood fiber gel material as a 3D printing material. A five-degree of freedom hybrid three nozzle 3D printer was designed. The structural analysis, static analysis, modal analysis and transient dynamic analysis of 3D printers were researched, and the theoretical basis of the 3D printer was confirmed as correct and structurally sound. The results showed that the 5-DOF hybrid 3-nozzle 3D printer achieved the 3D printing of wood fiber gel material and that the printer is capable of multi-material printing and multi-degree-of-freedom printing.