Electroforming of Personalized Multi-Level and Free-Form Metal Parts Utilizing Fused Deposition Modeling-Manufactured Molds.

Adapting to the growing demand for personalized, small-batch manufacturing, this study explores the development of additively manufactured molds for electroforming personalized metal parts. The approach integrates novel multi-level mold design and fabrication techniques, along with the experimental procedures for the electroforming process. This work outlines design considerations and guidelines for effective electroforming in additively manufactured molds, successfully demonstrating the production of composite metal components with multi-level and free-form geometries. By emphasizing cost efficiency and part quality, particularly for limited-thickness metal components, the developed technique offers distinct advantages over existing metal additive manufacturing methods. This approach establishes itself as a flexible and durable method for metal additive manufacturing, expanding the scope of electroforming beyond traditional constraints such as thin-walled hollow structures, 2D components, and nanoscale applications.

Rapid microwave-induced synthesis of gold-polydimethylsiloxane nanocomposites for biosensing of proteins.

In this paper a novel in-situ microwave-induced synthesis of the gold-polydimethylsiloxane nanocomposite is presented. Microwave-induced synthesis has the advantages of a very short reaction time, small particle size and narrow size distribution of the particles. The ethanol solution of gold chloroauric acid is used as the precursor solution. The mechanism of formation and growth of nanoparticles are discussed in detail. UV/Vis spectroscopy and SEM imaging were used to characterize the optical properties and the size distribution of the particles. To improve the sensing properties of the nanocomposite, an annealing process were used. The results show that the annealed samples have the high sensitivity of 102 nm/RIU toward the surrounding medium which makes the nanocomposite suitable for biosensing applications. In addition, the elasticity of the platform in the presence of gold nanoparticles was found to be enhanced up to 20%. Finally, the immunosensing of the bovine growth hormone was performed by using the localized surface plasmon resonance (LSPR) band of gold nanoparticles. The results demonstrate suitability of the nanocomposite platform for biosensing applications. The results are highly relevant for microfluidic-based biosensors.

Integration of gold nanoparticles in PDMS microfluidics for lab-on-a-chip plasmonic biosensing of growth hormones.

Gold nanoparticles were synthesized in a poly(dimethylsiloxane) (PDMS) microfluidic chip by using an in-situ method, on the basis of reductive properties of the cross-linking agent of PDMS. The proposed integrated device was further used as a sensitive and low-cost LSPR-based biosensor for the detection of polypeptides. Synthesis of nanoparticles in the microfluidic environment resulted in improvement of size distribution with only 8% variation, compared with the macro-environment that yields about 67% variation in size. The chemical kinetics of the in-situ reaction in the microfluidic environment was studied in detail and compared with the reaction carried out at the macro-scale. The effect of temperature and gold precursor concentration on the kinetics of the reaction was investigated and the apparent activation energy was estimated to be Ea*=30 kJ/mol. The sensitivity test revealed that the proposed sensor has a high sensitivity of 74 nm/RIU to the surrounding medium. The sensing of bovine growth hormone also known as bovine somatotropin (bST) shows that the proposed biosensor can reach a detection limit of as low as 3.7 ng/ml (185 pM). The results demonstrate the successful integration of microfluidics and nanoparticles which provides a potential alternative for protein detection in clinical diagnostics.

PDMS-gold nanocomposite platforms with enhanced sensing properties.

Gold-poly(dimethyl siloxoxane) (Au-PDMS) nanocomposite films with a high elasticity were fabricated for sensing experiments. The nanocomposite was prepared by a novel in-situ method by using the ethanol solution of the chloroauric acid. The high rate of permeation of ethanol in the polymer film, compared to an aqueous solution, allows the introduction of the gold precursor into the polymer network with a higher rate and, thus the reduction reaction is accelerated. The strong hydrophobicity of the as-prepared films precludes the diffusion of aqueous solutions of biomolecules in the polymer network, essential for sensing purposes. In order to modify the morphology and the surface properties of the samples, they have been heat-treated and the polymer network has been expanded mechanically by repeated swellings and shrinkages. As a result, the free volume of the polymer is increased substantially and thus, the biosensing capability of the material is improved. The effect of gold nanoparticles on the porosity and the mechanical properties of the material has been studied. The highest value of the sensitivity (around 70 nm/RIU) has been obtained for the samples that were annealed and, subsequently swollen in toluene. Biosensing experiments involving antigen-antibody interactions showed a high sensitivity. The results of this work are relevant for sensing in a microfluidic environment.