Size Of Microparticles Research Articles

A comparative analysis of PLA and PCL microparticles for hydrophilic and hydrophobic drugs.

This study aims to investigate Polylactic Acid (PLA) and Polycaprolactone (PCL) polymers for microencapsulation of hydrophilic and hydrophobic anti-glaucoma drugs using an emulsion-based solvent evaporation technique. Microparticle size was analysed using optical microscopy, while drug-polymer interactions through Dynamic-Light-Scattering (DLS) and Fourier-Transform-Infra-red/Attenuated-Total-Reflection spectroscopy (FTIR/ATR). In vitro, drug release studies were performed to investigate drug encapsulation and release profiles. Spherical microparticles, with particle size 94 ± 6.9 μm for PCL-based and 100 ± 3.74 μm for PLA-based formulation, were obtained. Drug release studies showed 100% release over about 32 days, with encapsulation efficiency (%EE) and drug loading (%w/w) reaching up to 95 and 2.84% for PLA-based and 97 and 2.91% for PCL-based microparticles, respectively. DLS studies reveal an increase in hydrodynamic radius (RH), which correlates to enhanced drug encapsulation. So, the nature of the drug and polymer significantly impacts drug encapsulation and release, with drug-polymer interactions playing a crucial role alongside experimental parameters.

Investigating reactive transport and precipitation patterns of calcium carbonate in fractured porous media

HypothesisUnderstanding calcium carbonate (CaCO3) precipitation in various polymorphs from nanoparticle size (amorphous calcium carbonate) to microparticle size (vaterite, aragonite, dendrite, calcite) is important for practical applications, including carbon geo-storage (e.g., basalt formations), hydrogen storage, groundwater management, and soil stabilization. Our hypothesis suggests that the interplay of Péclet numbers (Pe), Damköhler numbers (Da), and Supersaturation Index (SI) significantly impacts the evolution of CaCO3 precipitation in fractured porous media in terms of mixing patterns, spatiotemporal evolution, crystal morphology, crystal size, and clogging behavior. ExperimentsThis study takes a novel approach to explore the colloidal formation and precipitation dynamics of CaCO3 within a fractured microfluidic system. Here, calcium chloride (CaCl2) and sodium bicarbonate (NaHCO3) solutions were injected and reacted under varied Pe (0–11), Da (0–1), and SI (2–5). FindingsOur analysis revealed distinct precipitation patterns and mixing types, such as transverse, longitudinal, and incomplete mixing, providing insights into the behavior in fractured porous media. We systematically analyzed the temporal and spatial evolution of precipitation, demonstrating how Pe, Da, and SI dictate precipitation rates and spatial distribution. Additionally, the study uncovered a range of CaCO3 polymorphic forms, illustrating their evolution and coexistence. Morphological changes and crystal sizes were examined to decode nucleation and growth processes. Significantly, our findings highlight the relationship between precipitation and clogging in the fractured medium, offering a deeper understanding of reactive transport in complex porous environments. These insights are crucial for enhancing carbon containment security and storage efficiency in underground formations, improving groundwater remediation techniques, and developing novel construction materials through controlled precipitation processes.

Development and evaluation of an oral quinine sulphate sustained release formulation for the management of visceral leishmaniasis

Background: Visceral Leishmaniasis is a systemic disease caused by the invasion of reticuloendothelial cells in the liver, spleen, and bone marrow by Leishmania spp. parasites. Current medications have numerous adverse effects and some resistance has been reported. Most treatments are administered parenterally, leading to non-compliance and treatment failure. This study aimed to develop an oral formulation of quinine sulfate to address these challenges.Methods: Quinine sulfate was encapsulated in hydroxypropylmethylcellulose using the spray-drying method and evaluated for particle size, zeta potential, drug content, entrapment efficiency, and in vitro release properties. In the in vivo study, laboratory mice infected with L. donovani promastigotes were treated for two weeks.Results: The average size of the quinine sulfate microparticles ranged from 2.6 to 14.2 µm, with an entrapment efficiency of 93%. Oral formulations effectively cleared parasites from the organs.Conclusion: Orally administered quinine sulfate efficiently cleared parasites from the blood of infected mice and resolved infections in their organs.

Enhancing mechanical properties of 2024-Aluminium Alloy Matrix Composite strengthened by Y2O3 ceramic particles

The development of high-strength, low-weight composite materials has been a high-priority demand in the structural, aerospace, automotive, renewable energy, and sports equipment sectors. Micro-particle size Yttrium oxide (Y2O3) has been utilized to enhance the microstructure and mechanical characteristics of the 2024-Al alloy. The stir-casting technique is employed to prepare 2024-Al alloy and aluminum matrix composites (AMCs) with different Y2O3 weight fractions (1 %, 2 %, and 3 %). Scanning electron microscope ESM with EDS analysis and optical microscope imaging have been used to assess the development in the microstructure of AMCs. Furthermore, optical microscope images have been analyzed by using image processing software, ImageJ to evaluate development in microstructure grain size. Vickers' micro-hardness, tensile strength, elongation, and wear-resistant tests were conducted to assess the mechanical properties of AMCs. AMC image analysis results demonstrated a significant reduction in microstructure grain size. The highest reduction in grain size was recorded when adding 2 wt. % of Y2O3, which was approximately 22.5 % smaller than that of the plain alloy. Other mechanical test results demonstrated an increase in the hardness and tensile strength of AMCs compared with the plain alloy by approximately 58 % and 116 %, respectively, upon the addition of 2 wt. % of Y2O3, also tensile test shows increasing of AMCs elongation at failure point with increasing Y2O3 content, 132 % upon adding 3 wt. %. Finally, wear tests show a decrease in the AMC wear rate with an increasing Y2O3 weight fraction compared to the plain alloy.

Investigation of the Impact of Manufacturing Methods on Protein-Based Long-Acting Injectable Formulations: A Comparative Assessment for Microfluidics vs. Conventional Methods.

Therefore, rhCCL22-loaded poly(lactic-co-glycolic) acid (PLGA) microparticles were prepared by conventional homogenization and microfluidics methods. The resulting microparticles were analyzed comparatively, focusing on critical quality attributes such as microparticle size, size distribution, morphology, drug encapsulation efficiency, release kinetics, and batch-to-batch variations in relation to the manufacturing method. Our results demonstrated that the conventional method resulted in microparticles with denser surface porosity and wider size distribution as opposed to microparticles prepared by the microfluidics method, which could contribute to a significant difference in the drug-release kinetics. Additionally, our findings indicated minimal variation within batches for the microparticles prepared by the microfluidics method. Overall, this study highlights the comparative assessment of several critical quality attributes and batch variations associated with the manufacturing methods of protein-loaded microparticles which is crucial for ensuring consistency in efficacy, regulatory compliance, and quality control in the drug formulation manufacturing process.

Utilizing almond shell filler to improve strength and sustainability of jute fiber composites

AbstractIn recent years, natural fibers have begun to replace synthetic fibers in automotive, building, and marine applications because of their sustainability, renewability, low cost, and availability of raw materials. However, because of their low strength, biocomposites are strengthened by hybridization with stronger synthetic fibers or adding fillers. This study reinforced high‐cellulose jute fiber composites with cellulose‐based almond (Prunus amygdalus) shell filler (ASF). Natural waste almond shells were ground to microparticle size. Hybrid composites were prepared by adding microparticulate ASF to the jute fiber composites at 0%, 1.5%, 3%, 4.5%, and 6% by weight. A comprehensive experimental study included tensile, flexural, Charpy impact (flat and edgewise), and shear tests. The addition of ASF significantly improved the mechanical properties of the jute fiber composites, and the best values were obtained with 3 wt.% ASF addition. Tensile, flexural, impact, and shear properties increased by 48.2%, 63.5%, 24.4%, and 52.2%, respectively. Scanning Electron microscopy (SEM) micrographs used in morphological structural analysis prove that the high mechanical values are achieved by ASF strengthening the interlaminar adhesion. This study contributed to developing a hybrid natural composite material reinforced with natural fillers that is stronger, environmentally friendly, and sustainable.Highlights The organic structure of Almond Shell Filler (ASF) ensured the sustainability of natural composites. Cellulosic ASF significantly contributed to the structural stiffness and strength of jute fiber composites. ASF reduced voids, improved fiber‐matrix bonding, and prevented debonding and delamination. ASF optimized the mechanical performance of jute fiber composites at 3%.

Microencapsulation for the delivery of terazosin hydrochloride: design, development, and characterization

The aim of the work. Terazosin HCL, which is a selective alpha-1 antagonist, has been recommended for the treatment of benign prostatic hyperplasia-related medical conditions, including hypertension and urinary tract disorders. The purpose of this research was to create microparticles that would have a prolonged release of terazosin hydrochloride (TZ). However, TZ is a medicine that is readily soluble and has a high capability of dissolving in water. Materials and methods. A validated HPLC method was established to assess TZ. The TZ microparticles were produced using the process of melt dispersion by utilising cetyl palmitate (CP), myristic acid (MA), Glycerol monostearate 4055 (type II) or Kolliwax® GMS II (GMS), polyethylene glycol 400 (PEG 400) as a plasticizer, and tween 80 as a stabilizing agent. Different formulations of TZ microparticles were evaluated with regard to particle size, zeta potential, and release, and morphological scanning was performed. Results. A zeta potential that falls between -22.9 and -29.4 mV is possessed by TZ microparticles. Furthermore, the size of TZ microparticles falls between 2.11 and 5.60 µm, and the polydispersity index (PDI) was between 0.24 to 0.41. In addition, the formula (F4) that included CP, GMS, PEG 400, and Tween 80 in the proportions of 0.8:0.2:1:0.5 had the highest zeta potential (ZP) and dissolved more than 85 % of TZ after 8 hours. Therefore, F4 was chosen for the purpose of conducting morphological research. Conclusion. Employing the use of CP, GMS, PEG 400, and Tween 80 in a ratio of 0.8:0.2:1:0.5 could result in the generation of microparticles of TZ that are the most acceptable

Stretchable Anisotropic Conductive Film with Position‐Registered Conductive Microparticles Used for Strain‐Insensitive Ionic Interfacing in Stretchable Ionic Sensors

AbstractNumerous approaches are explored to achieve precise position registry of microparticles (MPs) with minimal defects; however, MP assembly in a periodic pattern or an arbitrary manner has been a challenging issue over the past several decades. Utilizing the position‐registered conductive MPs, polymer composites of the MPs are used as anisotropic conductive film (ACF) and soft interfacing. One of the remaining challenges is maintaining the MP positions while producing or utilizing the ACF. This study proposes a simple strategy to produce a stretchable ACF (S‐ACF) by mechanical rubbing, without disturbing the MP positions during the production and use. A practical means of precise MP positioning on a ultraviolet (UV)‐patternable soft template is investigated first. This study investigates, through both experiment and finite element method calculation, the relationship between local adhesion of the template and mechanical rubbing variables (pressure, rubbing velocity, and MP size). Based on this exploration, a fast and simple method to fabricate large‐area S‐ACF is presented. This study demonstrates that the S‐ACF can be used for electronic interfacing in stretchable devices and for ionic interfacing to remove the effect of external mechanical force in ionic sensors.

Dandelion inspired microparticles with highly efficient drug delivery to deep lung

Active pharmaceutical ingredient (API) embedded dry powder for inhalation (AeDPI) shows higher drug loading and delivery dose for directly treating various lung infections. Inspired by the dandelion, we propose a novel kind of AeDPI microparticle structure fabricated by spray freeze drying technology, which would potentially enhance the alveoli deposition efficiency. When inhaling, such microparticles are expected to be easily broken-up into fragments containing API that acts as ‘seed’ and could be delivered to alveoli aided by the low density ‘pappus’ composed of excipient. Herein, itraconazole (ITZ), a first-line drug for treating pulmonary aspergillosis, was selected as model API. TPGS, an amphiphilic surfactant, was used to achieve stable primary ITZ nanocrystal (INc) suspensions for spray freeze drying. A series of microparticles were prepared, and the dandelion-like structure was successfully achieved. The effects of feed liquid compositions and freezing parameters on the microparticle size, morphology, surface energy, crystal properties and in vitro aerosol performance were systematically investigated. The optimal sample (SF(-50)D-INc7Leu3-2) in one-way experiment showed the highest fine particle fraction of ∼ 68.96 % and extra fine particle fraction of ∼ 36.87 %, equivalently ∼ 4.60 mg and ∼ 2.46 mg could reach the lung and alveoli, respectively, when inhaling 10 mg dry powders. The response surface methodology (RSM) analysis provided the optimized design space for fabricating microparticles with higher deep lung deposition performance. This study demonstrates the advantages of AeDPI microparticle with dandelion-like structure on promoting the delivery efficiency of high-dose drug to the deep lung.

Protective Encapsulation of a Bioactive Compound in Starch-Polyethylene Glycol-Modified Microparticles: Degradation Analysis with Enzymes.

Starch is a promising polymer for creating novel microparticulate systems with superior biocompatibility and controlled drug delivery capabilities. In this study, we synthesized polyethylene glycol (PEG)-modified starch microparticles and encapsulated folic acid using a solvent-mediated acid-base precipitation method with magnetic stirring, which is a simple and effective method. To evaluate particle degradation, we simulated physiological conditions by employing an enzymatic degradation approach. Our results with FTIR and SEM confirmed the successful synthesis of starch-PEG microparticles encapsulating folic acid. The average size of starch microparticles encapsulating folic acid was 4.97 μm and increased to 6.01 μm upon modification with PEG. The microparticles were first exposed to amylase at pH 6.7 and pepsin at pH 1.5 at different incubation times at physiological temperature with shaking. Post-degradation analysis revealed changes in particle size and morphology, indicating effective enzymatic degradation. FTIR spectroscopy was used to assess the chemical composition before and after degradation. The initial FTIR spectra displayed characteristic peaks of starch, PEG, and folic acid, which showed decreased intensities after enzymatic degradation, suggesting alterations in chemical composition. These findings demonstrate the ongoing development of starch-PEG microparticles for controlled drug delivery and other biomedical applications and provide the basis for further exploration of PEG-starch as a versatile biomaterial for encapsulating bioactive compounds.

Rheological and textural properties of fish gelatine-microbial transglutaminase gel microparticles as thickener for texture-modified food

Gel microparticles are tiny, soft particles made from proteins or polysaccharides using particle size reduction. In creating texture-modified food and thickened liquids, gel microparticles are frequently employed to customise the rheological and textural features of foods or thin liquids. Gel microparticles aid by lowering flow behaviour, and modifying the taste perception of the texture-modified food. By cross-linking fish gelatine with the microbial transglutaminase enzyme (mTGA) using the homogenisation process, fish gelatine has tremendous potential to be used to create gel microparticles. The size measurements, texture profile, viscoelastic characteristics, and impact of sugar content on the texture profile of gel microparticles were all examined in the present work for the developed gel microparticles. The results of a particle size investigation revealed that gel microparticle sizes, which ranged from 18 to 1445 µm, increased with higher enzyme concentrations. With increasing mTGA concentration, the texture profile analysis (TPA) also revealed increasing values for hardness, adhesiveness, springiness, cohesiveness, gumminess, and chewiness parameters. The cross-linked gel microparticles had higher dominance on elastic behaviour than viscous behaviour from the rheological investigation, as evidenced by a higher G' compared to G". Additionally, larger TPA values were seen as the sugar concentration increased. These outcomes are anticipated because sugar will strengthen fish gelatine’s hydrogen bond. Based on all completed analyses, fish gelatine cross-linked with 0.7% mTGA to create gel microparticles has shown encouraging results, which can be used as a thickener in texture-modified food to aid those who have trouble swallowing.

Formulation and Evaluation of Polysaccharide Microparticles for the Controlled Release of Propranolol Hydrochloride.

Propranolol hydrochloride, a non-cardio-selective beta blocker, is used to treat several conditions in children, including hypertension, arrhythmias, hyperthyroidism, hemangiomas, etc. Commercial liquid formulations are available in Europe and the US, but they have disadvantages, such as limited stability, bitter taste, and the need for multiple daily doses due to the drug's short half-life. Considering these limitations, controlled-release solid formulations, such as microparticles, may offer a better solution for pediatric administration. The main objective of this study was to formulate an encapsulation system for propranolol hydrochloride, based on sodium alginate and other polysaccharide polymers, to control and prolong its release. Microparticles were prepared using the ionotropic gelation method, which involves instilling a polymer solution into a solution of gelling ions via the extrusion technique. Physicochemical characterization was conducted by assessing the entrapment efficiency, drug loading, swelling index, microparticle size, rheological properties, and surface tension. In order to improve the characteristics of the tested microparticles, selected formulations were coated with chitosan. Further experimental work included differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) analysis, and SEM imaging. This in vitro release study showed that chitosan-coated microparticles demonstrate favorable properties, suggesting a novel approach to formulating pediatric dosage forms, although further optimization is necessary.

Inhalable solid lipid nanoparticles of levofloxacin for potential tuberculosis treatment

Delivering novel antimycobacterial agents through the pulmonary route using nanoparticle-based systems shows promise for treating diseases like tuberculosis. However, creating dry powder inhaler (DPI) with suitable aerodynamic characteristics while preserving nanostructure integrity and maintaining bioactivity until the active ingredient travels deeply into the lungs is a difficult challenge. We developed DPI formulations containing levofloxacin-loaded solid lipid nanoparticles (SLNs) via spray-drying technique with tailored aerosolization characteristics for effective inhalation therapy. A range of biophysical techniques, including transmission electron microscopy, confocal microscopy, and scanning electron microscopy were used to measure the morphologies and sizes of the spray-dried microparticles that explored both the geometric and aerodynamic properties. Spray drying substantially reduced the particle sizes of the SLNs while preserving their nanostructural integrity and enhancing aerosol dispersion with efficient mucus penetration. Despite a slower uptake rate compared to plain SLNs, the polyethylene glycol modified formulations exhibited enhanced cellular uptake in both A549 and NR8383 cell lines. The percent viability of Mycobacterium bovis had dropped to nearly 0 % by day 5 for both types of SLNs. Interestingly, the levofloxacin-loaded SLNs demonstrated a lower minimum bactericidal concentration (0.25 µg/mL) compared with pure levofloxacin (1 µg/mL), which indicated the formulations have potential as effective treatments for tuberculosis.

A compound eye-like morphology formed through hexagonal array of hemispherical microparticles where an alkyl-fullerene derivative self-assembled at atmosphere-sealed air/water interface

Self-assembly processes are widely used in nature to form hierarchically organized structures, prompting us to investigate such processes at the macroscopic scale. We report an unprecedented approach toward the self-assembly of alkyl-fullerene (C60) derivatives into a hexagonal array of hemispherical microparticles akin to the morphology of a compound eye. The method includes casting solvated alkyl-C60 compound on an air/water interface followed by controlled evaporation of the solvent under atmosphere-sealed conditions. This leads to the formation of a thin film floating on water with a diameter of up to 1.3 centimeters and exhibiting a hexagonally-packed hemispherical structure with a diameter of approximately 38 µm. Various measurements of the formed film reveal that amorphousness is necessary for suppressing uncontrollable crystallization, which affects the microparticle size and film formation mechanism. We tested the feasibility of this approach for the self-assembly of a relatively common C60 derivative, [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), resulting in the formation of a film with a similar pattern of hexagonally-packed larger microparticles approximately 152 µm in size of diameter.

Exploiting flow manipulation to engineer the electroactive phase for improved piezo response in size tunable PVDF microspheres via microfluidic technology

Polyvinylidene fluoride (PVDF), a semi-crystalline polymer with remarkable piezo-, ferro-, and pyroelectric properties in its electroactive phase (EA), holds significant potential. Microfluidic-based techniques, particularly droplet-microfluidics, have become a preferred method for producing PVDF microspheres, offering advantages like size and shape adjustability, simplicity, efficiency, and effective heat dissipation. This article focuses on employing a microfluidic flow focussing device (MFFD) with thermal initiated off-chip polymerization to process PVDF microspheres. The MFFD disperses uniform droplets into an oil bath, initiating polymerization and yielding microspheres ranging from 126 to 754 µm. Fine-tuning flow rates achieves precise control over microparticle uniformity, monodispersity, size, and spherical shape. Optimization of reaction temperature (Toil) significantly enhances the EA phase, reaching 82.05 % at Toil = 60 °C. The resulting microspheres are comprehensively characterized for structure, morphology, composition, phase, hydrophobicity, biocompatibility, thermal, and piezoelectric properties. Additionally, machine learning analysis is employed to predict the mean diameter as well as the EA and β-phase of PVDF microspheres. A flexible piezoelectric device made from PVDF microspheres, demonstrating an open circuit voltage of ∼23.5 V in response to finger and foot tapping movements, showcases potential for self-powered wearable sensors and devices. This study underscores the synergy of microfluidics, polymer science, and artificial intelligence in advancing smart materials.

Copper-Decorated Titanium Electrodes: Impact of Surface Modifications of Substrate on the Morphology and Electrochemical Performance.

This study investigates the effect of surface modifications of the titanium substrate on the growth of electrochemically deposited copper. These materials are intended to serve as cathodes in the electroreduction of nitrates in aqueous solutions. Surface modifications included the use of hydrogen fluoride for titanium etching and anodization to promote the growth of a structured titania nanotube array. The effect of an intermediate calcination step for the nanotubes before deposition was assessed along with a comparison to an untreated substrate electrode. The materials were comprehensively characterized by SEM, XRD, contact angle, potentiodynamic tests, EIS, and cyclic voltammetry. Their electrocatalytic ability was tested in the reduction of aqueous solutions containing nitrates. The results reveal that surface finishing impacted the shape and size of the Cu microparticles, as well as the nucleation mechanism enabling a crystal-facet-controllable synthesis. All the materials exhibited microsized copper particles with a spherical shape with some clusters. On the etched titanium surface, a high number of heterogeneous submicroscopic particles were also present. The thermally treated anodized substrate promoted the development of a combination of sparse microparticles corresponding to defect sites in amorphous titanium and the presence of a diffuse coating of octahedral nanosized particles whose growth was promoted by the tetragonal structure of anatase crystals. Electrochemical tests display reduced charge transfer resistance upon copper deposition on the modified substrates, which is indicative of the enhanced conductivity of the coated materials. Additionally, cyclic voltammetry and electrolysis experiments reveal the electrodes' potential for nitrate reduction, showing a better response for the etched titanium substrate (30% nitrate removal, after 2 h at 25 mA cm-2).

Acoustic-assisted centrifugal microfluidics for particle/cell separation

The process of microparticle manipulation using acoustic waves within microfluidic devices is called acoustophoresis. This research focuses on a new approach for concentrating and categorizing microparticles using an integrated acoustic centrifugal microfluidic system with standing surface acoustic waves (SSAWs) and centrifugal forces. The study employs a rectangular microchannel with multiple inlets and outlets placed on an electrified lab-on-a-disc (eLOD) device subjected to SSAWs, guiding microparticles radially. Various physical parameters such as distance from the center of rotation, lateral displacement, tilting angle, microchannel dimensions, microparticle size, disc rotation speed, and applied voltage to the piezoelectric were simulated to assess microparticle focusing. The results indicate that adjusting lateral displacement and tilting angle can direct microparticles toward desired outlets. Enhanced focusing is achievable at low rotation speeds with higher applied voltage and narrower microchannel widths. The system's potential for classifying circulating tumor cells (CTCs) and white blood cells (WBCs) based on volume and density differences was also demonstrated. This acoustic eLOD device offers an efficient means for manipulating micro- and bioparticles.

Microencapsulation of Annona muricata L. seed extract for the control of Plutella xylostella

Insecticidal plants have stood out in Integrated Pest Management (IPM), associated with other control strategies, and therefore, the development of microencapsulated formulations, which make the active ingredient protected with slow and continuous release, becomes necessary. Thus, the present study aimed to develop, characterize and evaluate the lethal effect of the Microencapsulated Ethanolic Extract (MEE) from Annona muricata L. (Annonaceae) seeds on Plutella xylostella. MEE was developed in a B-290 BUCHI Mini Spray Dryer, using polymers starch, maltodextrin, gelatin and aerosil, and characterization was carried out through microparticle size and humidity, polydispersity index, morphologic analysis, Thermogravimetric analysis (TGA) and scanning electron microscope (SEM). MEE presented particle distribution with evident bimodal behavior, with diameters from 0.48 to 79.43 μm and polydispersity index equal to 6.414. Through SEM analysis, microparticles presented spherical and irregular shape, with smooth and rough/wavy, continuous, homogeneous surface, with variable size and external surface continuous in walls, with no apparent cracks. TGA demonstrated 5 decomposition stages, similar to the ethanolic extract. The estimated Lethal Concentrations (LC) for the ethanolic extract and MEE were: LC50 and CL99 of 0.204 and 5.675 g/L and 0.114 and 4.166 g/L, respectively. It could be concluded that the development of MEE was effective using the spray dryer method, with uniform microcapsules with insecticidal action able to be more soluble and persist the action of the active ingredient for longer times, improving its application in the field.

An Untethered Magnetic Microgripper for High‐Throughput Micromanipulation

AbstractMicrogripper is a small‐miniaturized robotic device employed to maneuver sub‐millimeter‐sized particles or objects that are too small to be manipulated by human hands or conventional tools. The design and fabrication of the microgripper pose challenges due to the integration of actuation components into their structure. To address this challenge, the authors in this work presented a novel magnetic microgripper wherein the functions of the actuation components are executed by the two pairs of microgripper arms made up of magnetic material. A custom‐made electromagnetic system consisting of eight coils is employed to externally control these arms, enabling precise execution of gripping up to a maximum of two microparticles per working cycle. By varying the magnetic field strength from 20 to 120 mT, a wide range of gripper‐arms opening distance is achieved, spanning from 0.3 to 1.3 mm. Consequently, the microgripper is demonstrated to grip different sizes of microparticles ranging from 0.3 to 1.2 mm. As part of the motion control capabilities, the microgripper is demonstrated to orient and navigate across a 360‐degree range within the microfluidic environment. The presented microgripper holds promise for manipulating a wide variety of microparticle sizes and shapes, offering potential for high‐throughput applications

Fabrication of RC filters from a single printed Zn layer by reactive inkjet printing

This paper presents the development of planar zinc (Zn) resistor–capacitor (RC) filters from a single printed layer that are both printed and treated at room temperature. The fabrication process involves screen printing the resistor, capacitor and interconnects in a single patterned layer on kraft paper substrates using a Zn microparticle ink. In order to form a distinct resistor and capacitor in the patterned structure, reactive inkjet printing (RIJ) was performed to selectively dispense acetic acid on the RC filter pattern to achieve regions with highly contrasting resistance. The required high degree of spatial contrast was achieved using the positional control of the inkjet printer combined with the number of print passes and drop spacing used to dispense the acetic acid droplets. X-ray diffraction and scanning electron microscopy showed the crystal structure and grain size of Zn microparticles remained unchanged with increasing acetic acid exposure while the prominence of cold-welding increased with increasing exposure. Zn-based RC filters sharing a common set of dimensions but with a wide range of corner frequencies were successfully fabricated using this process. For a fixed filter geometry, the corner frequencies could be tuned from ∼7 kHz to ∼1 MHz as the number of print passes used to form the resistor increased in a stepwise manner. To the best of our knowledge, this is the first room temperature printing process to produce side-by-side resistors and conductors from the same printed layer and the first printing process of any type to produce RC filters with such a wide range of corner frequencies.