In recent years, organic solar cells became more attractive due to their flexible power devices and the potential for low-cost manufacturing. Inkjet printing is a very potential manufacturing technique of organic solar cells because of its low material usage, flexibility, and large area formation. In this paper, we presented an overall review on the inkjet printing technology as well as advantages of inkjet-printing, comparison of inkjet printing with other printing technologies and its potential for organic solar cells (OSCs). Here we highlighted in more details about the viability of environment-friendly and cost-effective, non-halogenated indium tin oxide (ITO) free large scale roll to roll production of the OSC by inkjet printing technology. The challenges of inkjet printing like the viscosity limitations, nozzle clogging, coffee ring effect, and limitation of printability as well as dot spacing are also discussed. Lastly, some of the improvement strategies for getting the higher efficiency of the OSCs have been suggested.

Algal turf scrubbers (ATSs) have been used for water remediation in many applications, generating benefits such as water quality improvements and biomass production. Their economical operation is hampered, however, by uncontrolled mixed microbial communities, typical of open cultivation systems that result in lower biomass quality. Design of substratum topography is one approach to control the algal community composition by constraining colonization dynamics. This study seeks to elucidate the role of substratum topography on biomass productivity of benthic algae in an ATS environment. A set of tiles with custom-designed textures of repeated hemispheres across a range of diameters were 3D printed and cast on ceramic clay. An algal turf community dominated by Mougeotia taxa was cultivated on the tiles in a laboratory-scale ATS and harvested for biomass measurements after 21 days. Results show higher biomass on the topographies formed of 500 and 2,000 μm diameter hemispheres, with 74.3% more attached biomass than the 1,000 μm hemisphere and smooth topographies. With the surface area, material roughness at the microscale, and surface chemistry discarded as factors by experimental design, surface topography, especially interstitial space distribution, at the millimeter scale is shown to be a factor in the kinetics of algal cell colonization and growth on surfaces. This study is among the first that specifically focuses on the application of substratum design using additive manufacturing to improving the ATS process. These results can have a significant impact on design of next-generation high-productivity attached growth algae systems.

Stereolithography (SLA) additive manufacturing is a method of manufacturing capable of generating complex geometric shapes with extremely high accuracy. Classic SLA uses UV curable resins, particularly polylactic acid (PLA), for part generation, but recent research has focused on utilizing this technology for the generation of various composite materials. There has been success in manufacturing composite materials using this technology, but little research has been performed on the generation of carbon-fiber-reinforced composite materials. Carbon fiber stereolithography (CF-SLA) is often overlooked due to carbon fiber’s natural inability to bond with PLA. To overcome this boundary, surface modification techniques were used on chopped carbon fibers to achieve greater bonding. Here, two modification techniques were explored: a sodium dodecyl sulfate (SDS) surfactant addition and nitric acid (HNO₃) etching. These methods were used to functionalize and prepare the surface of chopped carbon fiber (CF) for bonding with cured PLA resin. Treated fibers were dispersed in generic PLA resin, and tensile test specimens were printed for examining the reinforcement potential of the two treatment methods. Additional complexities arise during printing with fibers including fiber alignment, accumulation, and fiber fallout. To address these issues, a novel in-process mixing method was developed to maintain fiber dispersion. A two-level three-factor factorial design was performed for both treatment methods to determine optimal printing parameters. Through mechanical testing, atomic force microscopy, scanning electron microscopy, and contact angle measurements, the accompanying material property changes were characterized to further develop the field of fiber-reinforced liquid crystal display (LCD) additive manufacturing. After testing, it was found that composites created with SDS nanoparticle modification were stronger than both the acid etched fiber sample and plain PLA. Specifically, SDS surface treatment resulted in a 15% increase in modulus and maximum strength of the sample, mainly by enhancing the interlayer bonding between CF and PLA.

Unsaturated vegetable oils with conjugated carbon–carbon double bonds, such as tung oil, can undergo free-radical polymerization, originating alternatives to petroleum-based materials. The introduction of fillers to vegetable oil-based polymer matrices results in composites with improved mechanical properties. In this work, thermosets were synthesized by the free-radical polymerization of a mixture of tung oil, divinylbenzene, and n-butyl methacrylate, and reinforced with bio-based fillers, namely Miscanthus, Pinus taeda (also known as southern pine), and algae (Microspora and Oedogonium) biomass. The effect of filler particle size on the composites’ properties was evaluated. Additionally, to develop a better interaction between the hydrophobic resin and the hydrophilic reinforcements, and improve the mechanical properties of the composites prepared, itaconic anhydride, a bio-based molecule derived from itaconic acid, was added to the resin. Thermogravimetric analysis (TGA) showed that the presence of itaconic anhydride improved the overall thermal stability of the composites. The storage modulus of the composites at room temperature, assessed by dynamic mechanical analysis (DMA), was increased by approximately 32% and 68%, for Miscanthus and southern pine composites, respectively, when itaconic acid was added to the resin. It was also observed that the glass transition temperatures were not significantly affected by the presence of itaconic acid. Scanning electron microscope (SEM) images indicated better matrix-reinforcement adhesion in the presence of itaconic anhydride.

The increase in the demand for additively manufactured parts and the drive toward a sustainable economy with less environmental pollution has triggered the need for renewable materials for use in 3D printing. This study shows how the final properties of stereolythography (SLA) 3D-printed parts are affected by the number of carbon–carbon double bonds in vegetable oils used to prepare biobased free radical resins. The free radical resins developed in this study contain a minimum of 95 wt % biobased content and are readily polymerizable using a commercial SLA 3D printer. Two distinct vegetable oils, namely soybean and linseed oils, were epoxidized and then acrylated. The epoxidized, acrylated oils and their 50:50 (wt/wt) blend were used to demonstrate the influence of carbon–carbon double bond content on the final properties of SLA 3D-printed parts. The synthetic strategy adopted was successful and showed promise, leading to printed materials with good thermo-mechanical properties. More specifically, it is demonstrated herein that the degree of unsaturation of the oil has a direct impact on the tensile strength of parts printed via stereolithography, and that final properties can be tuned by blending resins prepared from different oils. Ultimately, parts printed with linseed oil displayed better properties than those printed with soybean oil.